Rodents Damage Cars By Chewing Electrical Connections: Tips On How To Avoid Costly Repairs

October 6, 2011

I am not a vegetarian, but would be if I had to kill what I ate. I even brake for skunks. But after having two of my car’s electrical systems chewed up my mice, I am more than happy to kill the little rodents.

The second time was in September when the dreaded Check Engine Light came on my 2010 Honda Pilot. No big deal, I thought, since it was still under warranty.

Took the car to Hoffman Honda in Avon, where I discovered it was not a minor matter. Mechanic Steve Moreau checked his diagnostic tool and found that one of the sensors – a crucial one impacting the catalytic converter – was shot.

Steve (gombossy photos)

He popped the hood and to my surprise found a nice mice nest on top of the manifold and the remains of a chewed wire dangling off the sensor. It would have been a minor problem, were it not for the fact that the wire went under the manifold, requiring several hours of work as the top of the engine had to be removed.

My car is just one of hundreds of thousands of vehicles that are damaged by rodents every year. The cost of repair can run anywhere from $50 to thousands of dollars.

Rocky Subramani, my service advisor at Hoffman Honda, told me that more than 100 cars were brought to his dealership in the past year because of rodent damage to electrical systems.


“We had three cars just this week,” he told me Wednesday. The most expensive job was $1,000, but he has had electrical damage that exceeded $3,000 in one vehicle where the rodents chewed up the body harness.

So what makes our vehicles attractive to mice and other rodents? Heat and smell.

Subramani warns customers to clean all food – including sealed bags – out of cars, especially nuts and dog food. Also, anything that smells sweet like vanilla air fresheners.

Steve points out the nest and chewed wire.

There are all kinds of tools available on the Internet to try to keep the little varmints out of your car – anything from $20 magnetic mothball holders to thousand dollar metal barriers around your parked vehicle.

He said mothballs in the engine compartment helps keep rodents out. Some have used dryer sheets, liquid peppermint or coyote urine on cotton balls.

Subramani said the first thing people should do is regularly pop the hood and look for signs of a nest or droppings. Considering that this is the second time in three years I have had this problem – the first involved my Mini Cooper – I have scheduled that monthly check now on my outlook for both vehicles.

And both vehicles are loaded with mothballs under the hood.

Rocky's photo of car damage from mice

Editor’s note: is a consumer auto guide which CtWatchdog Editor & Publisher George Gombossy helped  create,  provides editorial guidance and advertising in return for a marketing fee. The columns that published from are not only edited by George, they are sometimes, suggested by him. In full disclosure, George’s son Ethan Gombossy is the Porsche service representative for Hoffman. And of course from time to time Hoffman dealerships pay for advertising on George also purchased his company vehicle at Hoffman prior to entering into the marketing agreement. Obviously George has a huge conflict of interest and therefor cannot publish any positive or negative comments from readers about Hoffman Auto Group. As he has in the past, he forwards any complaints he recieves to co-owner Brad Hoffman.

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57 Responses to Rodents Damage Cars By Chewing Electrical Connections: Tips On How To Avoid Costly Repairs

  1. Patricia Ross on October 6, 2011 at 11:01 am

    I had the same problem last year. I solved it with poison in my garage which kept the rodents away all year. But before I went to poison, I used cayenne pepper sprinkled on the manifold, that worked until I found evidence of them in my glove compartment they ate a candy bar and part of my registration. And they disovered them in the trunk. D Con is the way to go!!

  2. Bill G. on October 7, 2011 at 8:20 am

    You would think that someone who writes about cars would know that it is “brake” , not “break”! (2nd sentence)

  3. Bill G. on October 7, 2011 at 8:22 am

    Instead of poison, Patricia, get rid of the food in the car! That’s why you had the mice in the first place.

    • phebe chin on July 7, 2012 at 2:20 pm

      My toyota camery only 4 weeks old. How long to take rodent eats wiring. I feel that this camery stores in the Santa Monica storage area for 10 months? We don’t have rodent at Play Del rey or our home. Why Toyota did not warn their customers? The wiring was made with soy product?

      • Sharon Suddeth on February 19, 2013 at 1:29 pm

        I also have a new Camry wtih rodent damage. I live in South Carolina. We do not have a rodent problem. My car only had a little over 100 miles when we had to pay for wiring harness to be replaced. Your comment about soy in the wiring is very interesting,how did you learn that? Have you had any other problems? Now my car is in shop with a transmission which may have to be replaced. Did Toyota take any responsable for your wiring repairs? Please take the time to reply.

  4. George Gombossy on October 7, 2011 at 8:24 am

    Thanks Bill, I changed it

  5. Debby on October 11, 2011 at 8:33 am

    Could we have more specifics on exactly where one puts mothballs in the engine compartment ?? I can’t quite envision just sprinkling them around in there !

    I also like ” Mouse Magic” by Bonide, which are tea bags filed with a special grade of oil of peppermint granules used by the grain industry to keep rodents away. Found at Agway, they are ridiculously expensive, however.

  6. George Gombossy on October 11, 2011 at 8:57 am

    Good question Debby. I used electrical tape to attach mothballs to areas of the engine that are cooler. You can also purchase magnetic containers that you can fill with mothballs.

  7. George Gombossy on October 11, 2011 at 8:18 pm

    George, I read your article concerning car wiring being eaten by rodents and what you thought attracted them to the wiring. while I am sure your theory makes sense, I have been in the auto repair business for over 45 years, I have owned my own shop for 33 years and I feel qualified to answer your question.
    After many years of finding wiring chewed up by rodents and wondering why we had not seen it with such vengence in the past, I decided to do a little research. In the process I came across an article written in “Motor Age” magazine about a year and a half ago that explained the dilemma. It seems that in an effort to make automobile components more “Green” and environmentally friendly, manufacturers of automotive wiring use “soy” in the production of the insulation for the wiring. The rodents are attracted to the soy which they can eat without much difficulty to their digestive system. I hope you find this information of interest. I just had to find out why — it’s just the mechanic in me — I needed to find the cause!!
    Thank you for allowing me to share this with you. (note) “Motor Age” magazine is published by monthly Hearst Publishing for the automotive trade.

    Richard C.Onofrio

    • lasey on May 20, 2013 at 9:53 pm

      You are exactly correct. Just had to take my 6-month old 2013 Honda Pilot to shop due to “check engine” light. Put it on portable checker & raised hood. Mouse chewed wiring to “knocking” sensor which lies several layers into engine ~$500 and of course it is not a warranty item (at least at this point-I’m not thru with them). Tech told me protective coating on wiring has “corn” component but maybe he meant soy. I thought he was just kidding but he said no, it was true. Corn or soy, both are grains which mice eat. Don’t these people have brains to think? Had a 2001 Hyundai and a 2007 GMS Sierra parked in same spot before and never had a problem. Obviously a known product defect they are not taking care of. Is there a class action lawsuit going on out there somewhere? I’ll sign up. Would hate to think I have to get rid of Honda to stop problem.

  8. richard griggs on October 12, 2011 at 6:07 pm

    the best thing to keep rodents out of your car is Peppermint oil just put some in small bottle caps around the car and mice won’t bother it. also if you spill some it won’t harm you ,i get it at the health food store.
    Richard Griggs

  9. Elwood Stagakis on August 29, 2012 at 6:28 am

    Use drawstring cloth bag tied under your hood or trunk to hold moth balls, peppermint or dryer sheets

  10. kyle on May 3, 2013 at 12:33 pm

    A Rid-A-Rat is a devise that works on light technology developed by a retired aerospace engineer and a animal behavioral specialist. It makes the environment irritating for any animal to stay. It is green,made in the USA by Americans and harmless to pets. They also give a 100% money back guarantee.
    RId-A-Rat’s labs have 100s of hours of video tape of all the urban legends and products that they tested and proved most of them didn’t work.

  11. Velda Bruce on May 7, 2013 at 1:55 pm

    We’ve been having problems with rodents, probably mice eating the lines to our gas tank. Any ideas to get rid of these critters?? Thanks in advance!

    • Merph on May 23, 2013 at 11:23 am

      Me too; if you find a solution or even a suggestion, please let me know. I have lost two fuel lines and now a tank filler tube.

  12. Elizabeth on August 2, 2013 at 10:19 pm

    I have a brand new 2012 Toyota Highlander with 11,500 miles. In July, my AC started running with no key in the ignition and the key remote control to lock & unlock the car was not working…..but I noticed all this happening after I would take it through a car wash or if we had a heavy rain. This prob happened four times in two weeks. I took it to the dealership and they discovered that a rodent had gotten in and eaten two major cables of some sort -$6400 worth of damage/parts & labor. I was responsible for $500 from deductible, which is annoying since it is a new car from Toyota. I will be contacting Toyota in regards to the GREEN parts that they may be using which is attracting these problems.

    • Pam on March 5, 2014 at 4:05 pm

      Any luck after contacting Toyota Elizabeth? This is my 4th occurrence of rodent damage and I’m out of $2,000 thus far-thanks.

    • Terry on January 5, 2015 at 10:51 am

      I am wondering if you had any luck with Toyota also, I have same problem with my Toyota.

  13. Kat Bray on August 7, 2013 at 6:19 pm

    Same problem here with a 2008 Nissan Altima. Seems ridiculous that manufacturers that came up with the swell idea of using soy can’t come up with a viable solution to the problem. But then why bother?? My car came out of the shop one week and was back in the next with wires chewed and another $1500 transmission harness ordered. Cha ching. Saw on another site Honda dealer does actually offer a tape with capsaicin to wrap wires with.
    Sorry you’ll have to copy and paste the link. I had the dealer spray the wires with a product called RapLast. It’s made to spray on leg wraps used on horses to keep them from biting at them. It has capsaicin it in as well. Can be sprayed or painted on with a brush but BE CAREFUL. Warning on bottle to make sure you are downwind. Don’t get it on you.
    Good Luck!

  14. Elizabeth on August 10, 2013 at 8:23 am

    Thanks Kay for the tip….I will check into ordering some of that tape!

  15. mary herald on August 14, 2013 at 10:54 am

    I find that the car manufacturers could infuse a repellent into the insulation if they so desired or a at least warn the customers of the possible problems however we as consumers always pay the price but I as a consumer will insist that i am informed of any green products that are use in the next vehicle I purchase and I will not buy it until they can insure me that if there is a problem they will fix it at their cost. when more consumers start guarding their purchases like that then perhaps we can see a change in the way people are treated

    • Chris on January 20, 2015 at 2:00 pm

      Sure a repellent could be added, then you’ll complain of higher service costs due to technicians needing additional protection to work on “repellent infused” wiring and components…
      Why should the manufacturer pay for a repair due to an animal damaging your vehicle? (That’s what car insurance is for!)…

      • Dar on January 25, 2015 at 11:29 pm

        What a ridiculous answer, that car insurance is for that purpose. It is not so that manufacturer’s can recklessly keep putting a material in a car that is attractive to rodents. Why should I pay $20K to $30K or more for a vehicle so that it can get major damage because of the material it has been made with? Apparently you’ve not had a problem such as this. Hopefully you will continue to be one of the lucky ones. I’ve had the problem twice on a 2013 Hyundai, to the tune of $4000 the first time and $5000 the second time. And no sign of rodents in my garage, where the vehicle is kept most of the time. And what happens if insurance companies stop paying for this damage, putting a disclaimer in the policy? Why should they foot the bill because of poor design by the manufacturers? A car is meant to be outside. It should not be made of materials that are attractive to rodents or animals of any kind.

        • Elisa Brown on March 22, 2015 at 7:37 pm

          I agree!

  16. jeff on January 16, 2014 at 10:15 am

    got into my car on cristmas eve check engine light was on car had no power. turns out rodent had chewed through knock sensor wire and ground wire for computer 300 dollars later all is fine im gonna fire my cat

    • lori on January 1, 2015 at 1:26 pm

      Odd…same thing happened to me this past Christmas Eve (2014). I went to start my car and my power steering was gone. Fortunately for me, my son said it could be the belt. He came over and he found a dead rat laying under the belt (that was off). It ran right over the rat and you could see the belt mark across the body. This is the second time I have had a problem. Last time they chewed up my wiring they made a 12″ hole in the insulation under my hood. My car started skipping so bad I didn’t think I could make it to my mechanic. It cost me $400 that time (I haven’t replaced the insulation unit yet). The day after the belt came off I discovered my A/C isn’t working. Wonder how much that will cost me.

  17. jj on March 23, 2014 at 4:29 pm

    it seem to me that the car manufactures r making a lot of money by making soy or corn for the wiring in your cars. the rodents r getting fed and the manufactures r making more money on repairs then what your car is worth. we need to stop buying cars that doesn’t protect the consumers with a warranty on this matter

    • Chris on January 20, 2015 at 1:44 pm

      I’m sure the auto manufacturers are purposely using these products to attract rodents and dwell up more business.. smh!
      Guess ya want a warranty from clothes manufacturers againest moths and your home warrantied if its damaged by hail too?

  18. bobnj on July 2, 2014 at 11:31 am

    Rodents three times chewed thru my 2004 Pilot’s gas line between the gas cap and the tank. A friend of mine put a hose sleeve around the gas line and stopped the problem. It’s a plastic corrugated hose cover normally used for radiator hoses. It is slotted lengthwise and installation was trivial. I did try the hot sauce by the way and doesn’t seem to effect these squirrels :-)

  19. Randolf Scott on July 15, 2014 at 5:49 am

    My 2013 Hyundai Sonata received 400.00 worth of rodent damage under the hood Thanks to soy

  20. gale vance on August 28, 2014 at 3:14 pm

    I would like to take action. What is the first step I should take? I had the problem in my Sienna and now in my 2013 Rav 4.
    I park next to an older Saturn and a Ford Explorer. They have no problems with rodents in the engine as I have.

    • Elisa Brown on March 22, 2015 at 7:08 pm

      why should we have to do this, Toyota should come up with a fix. I have owned Toyatas since 1978 and never ever had a problem ’till I purchased a 2012 Toyota Prius. Constant problem is stressing me out. Ant class action lawsuits out there? I’ll sign. Elisa Brown

  21. KAB on September 6, 2014 at 2:36 pm

    Brought my brand new bmw 328d home on Sunday night. Friday morning the steering didn’t work. Turns out the soy-based wiring insulation attracted rabbits or rodents who chewed through the wire. Soy!

  22. robin r on September 23, 2014 at 10:58 am

    The check engine light on my 2009 mercedes sedan came on. The dealer asked me if I parked my car outside and not in the garage. I told them, for the past 12 years I have parked my vehicle outside!
    Photos from the mechanic show mouse/mice feces and damage to a wire caused by the rodent getting inside my engine. There was no evidence of the mouse/mice in the trunk or drivers side. Repairs came to $500.

  23. kirk on October 23, 2014 at 9:50 pm

    Just purchased a new 2015 Sonata here in Las Cruces NM last week. Spending $500 dollars tomorrow @ Borman Autoplex due to this very issue. WIFE AND I ARE PI_SED!! Haven’t even made the 1st payment on our new car yet!!

  24. John Dale on November 17, 2014 at 10:54 am

    I would like to take action. I have a 2013 Rav 4.
    It needed a new wiring harness due to mice. I have 6 oth
    6 other vehicles parked nearby and none of
    Them ever has had this kind of problem. Is’nt
    It time Toyota took responsibility for this problem!

    • Elisa Brown on March 22, 2015 at 7:31 pm

      I’m with you. Now have no dashboard when headlights on.

  25. Bob Martin on December 3, 2014 at 6:14 pm

    over a year ago rats ate a wire in my car, a fuel injector wire i believe, anyway the car is quite old and i am quite poor…after the incident expensive electrical components started going out and the shope replaced them one by one, the check engine light coming on again usually before i even got the car home…first it was the mass air flow sensor that went, then the o2 sensor, then the engine control module, then the distributor…now the throttle position sensor…and possible the catalytic converter…i have been 98 percent without transportation for over a year now…is there any way this could have been a chain reaction caused by the rats eating the wires since the car was running perfectly then? if so than perhaps the insurance i had at the time can help since i did have comprehensive at the time…but i would have to be able to make a pretty good case and i do not know how…this situation has become life threatening to me as i am disabled and as a former alzheimer’s caregiver to my mom i have not had a paycheck in 25 years so being stranded has kept me from being able to look for work or get foood or medical care and it is now very much an emergency. i do not know what to do. the car is an 89 mitsubishi galant with 96k miles on it. urgent…somebody please help me.

  26. Ken Mergenthaler on December 8, 2014 at 2:24 pm

    Northwest suburbs of Chicago, my repair shop is on its 2nd visit from a 2010 Tundra in 1 month, major rodent damage each time. Insurance company involved.Wiring,anything plastic, firewall insulation etc… The soy wiring sounds like a good possibility. Trying to give our customer some ideas to stop this.

    • james on December 17, 2014 at 1:07 am

      TomCat makes a mouse poison that is a solid material encased in plastic housing (protects children, etc.). I place one in the cab on the floor under the seat and one under the hood (jammed in a tight place away from engine heat). Have noticed mouse dropping around the canister under the hood. No mercy for mice after $2000 repair on 3 vehicles. Snap traps on top of the tires may work if you stake them in the ground on a stick so the trap comes off of the wheel but out of tread tracks. See if these ideas work.

  27. terry on January 5, 2015 at 10:48 am

    I have brand new Toyota prius hybrid, purchased may 2014,it has been in the garage now since Dec 27th today Jan 5th a mouse chewed on our wires, of coarse not under warranty, we were told that any where from 500. to thousands of dollars in damage we still have no word as to when we will have are car back and they would not lend us a car, not impressed

  28. Sherrie Capelle on January 5, 2015 at 5:09 pm

    My car is a 2013 Honda Accord I just took it in because all my service lights came on, dealership says its being eaten by rabbits, there are literally hundreds of rabbits and squirrels here in Denver,dealership says to use dryer sheets which is impossible, its snowing here all winter and I’m not about to figure out how to climb under my car to tie on a dryer sheet, why do they make wiring out of soybean? Not covered under the warranty either, which that’s their problem for making the wiring that attracts rodents.

  29. Karen on January 6, 2015 at 1:07 am

    I have 2 cars sitting in the driveway. One is a 2012 Honda Fit that I purchased new 2 years ago. The other that hardly gets used or moved is a 1997 Nissan Altima. Two sensors (VSA/ETC and check engine light) came on. When I went to the dealership to check the codes, they couldn’t get any. They chewed through the wiring harness which prevented the codes from being returned. Luckily, the Honda dealership told me to contact my insurance and it was covered under my comprehensive coverage.

  30. Barry Skeels on January 11, 2015 at 10:39 am

    I have enjoyed reading of other peoples expériences in this very curious problem. It does’nt, however reveal why the little bastards eat this stuff, surely they can’t digest it? I went to the U.K. at Easter 2014 to collect a Renault Laguna that had been stored in a barn for 6 months, predictably it would’nt, flat battery etc.,despite being in superb condition.

  31. Barry Skeels on January 11, 2015 at 10:56 am

    The problem was found by a local mechanic in minutes. Mice had eaten most of a small rubber ‘bulb’ in the deisel fuel line, intended to pump up the fuel should you run out. Even more bizare, my girlfriend had exactly the same problem, only last week,(February 2015)Identical car but parked outside.Merde what to do?????? Bretagne. France

  32. Barry Skeels on January 11, 2015 at 11:14 am

    It seems to me that U.S., U.K. & French mice all read the same cookbook!

  33. patti hale on January 16, 2015 at 12:29 am

    2013 Honda Fit, 9000 miles. Took it in to only to find extensive rodent damage to major motor harness. Wires chew through. I’ve never had a rodent problem. $2905. To fix it. This should be a class action suit against these manufacturers.

    Why should they care our autos are being eatten due to their policies. They don’t have to fix them. Thousands of car have been damaged. Heck the rodents are attracted to the “green” products.

    I’m now worried this will recur.

  34. Srikrishna on January 20, 2015 at 4:35 am

    I am from India. I found my recently bought Nissan Micra CVT wiring harness bitten by rats. Symptoms before finding are – ineffective air conditioner performance, low response to throttle, shaking of the vehicle and steering, and finally the ENGINE LIGHT check. I thought it a foul play initially but later found orange and banana peels under the hood. These little villains are having them as a side dish to soy wiring. At last I found the cause through this site.

  35. Jaime on January 21, 2015 at 6:32 pm

    Insurance may cover damage under Comprehensive insurance as a peril! I have a 2013 Honda Fit and recently had some rodents chew through my transmission wire harness. Insurance would cover replacement after I paid my $500 deductible, but the tech at the dealership was awesome and quoted me $420, I asked if they had any discounts, he had a manufacturers coupon that gave me 12% or something, now it was reduced to $370. I still used Progressive to file a claim and they covered the cost of having a rental car for up to $30/day. Don’t be afraid to use your insurance if it is covered, that’s why you pay for it!! My agent also informed me that it would not affect my rate like a claim under collision coverage. Still…I will be using something to repel those stinking rats from my car. I hear cayenne pepper might work.

  36. shoopmom on January 22, 2015 at 4:30 pm

    Today marks the second time in as many months as I have taken my 2013 Chevy Sonic in to have the wiring harness replaced! Both times they said it was from mice or rabbits. We live in rural Wyoming with no garage! I have a .22 and have declared war on the rabbits around, but will have to take other measures to deal with the mice!

  37. Josh on February 17, 2015 at 6:14 pm

    Found that rats had eaten wiring in my 2014 Mazda CX-9. $600 in damage if they “fix” the wiring, thousands if they replace the harness. Since I have a $500 deductible I’m all for replacement. Going to rub Habenero all over the wiring in the car and see if the problem goes away.

  38. Mike on February 18, 2015 at 1:51 pm

    We had our car in for service due to a check engine light as well. Found mice nesting and chewing wires under the engine cover, an area we cannot see by just popping the hood. A few hundred dollars later and a tip from our mechanic led us to a unit called the mouse blocker. We had one installed and have been trouble free for some time now.

  39. David Sundstrom on February 20, 2015 at 3:18 pm

    Add to the list a two month old 2014 Ford expedition. $1400 to repair. Dealer told me this is not uncommon for F150s.

  40. Valerie Sandli on February 23, 2015 at 2:40 pm

    We have a 2014 Chev Tahoe…this is the 2nd time something has chewed up the dust cover the the steering joint in our engine….is this dust cover also made with soy products and how do we stop whatever is chewing it…never had problems with any other vehicle..we also have a 2012 problems…

  41. Kathleen Carosi on February 24, 2015 at 11:58 pm

    Dealing with this issue on my 2001 Toyota Prius paid $2,300 to fix it drove 35 miles and now they need another $2,000 to fix another part of the wiring that they had worked around the first time ($1,000 for parts, $1,000 for labor) the frustrating part is there are three cats that roam the neighborhood and I haven’t seen any evidence of droppings or the critters themselves in years. Calling the insurance company tomorrow and appreciate all the types on prevention. You would think with these issues happening on a regular basis car manufacturers would develop a way to make stronger wires.

  42. lisa henry on February 27, 2015 at 5:56 pm

    i’ve got a 2001 toyota camry that has been my reliable friend for 14 years, started up this a.m. running rough for the 1st time in all that time. My check engine light came on and then started blinking! checked my owners manual and it doesn’t even list an option of the check engine light blinking. i looked under the hood but actually didn’t see anything wrong. limped to my mechanic who informed me my wiring harness was chewed by rodents. i thought he was kidding at first but other people in the shop were agreeing with him. $700 bucks and my car is fixed and i now know rodents are chewing up car wiring on a regular basis. we’ve been having really cold weather so all i can think is the little monsters found my warm engine during last nights’ coldness and made it into a bed & breakfast. i’m using dryer sheets until i can go get some mothballs but i’m gunning for the little ba*tards now! :(

  43. P. Duncan on March 3, 2015 at 7:26 am

    I had the same issues with squirrels chewing the gas lines in my 2013 & 2014 Toyota Corolla’s & had to have the gas lines/tanks replaced in both cost $1000.00 for each car; used my deductible for both.. After much research for this issue I found 2 things: #1 putting dryer sheets in the trunk & tucked under rear tires at night (my former bosses recommendation) # 2 I spray the around the bottom of the tires with a great but stinky product called Shotgun Repels-All Animal Repellent by Bonide Products (see their website) which I get in Wal-Mart & Home Depot(Great Product).. Another good thing is to mix cayenne pepper with vinegar & spray that around the base of the tires also; works & stinky too.. I keep a box of dryer sheets in my trunk & replace the ones I toss in the trunk monthly.. I also spray around my garbage cans with the Shotgun Repels-All mine is the only garbage can untouched by squirrels in my area I also use those Mint-X garbage bags ‘excellent’ get in Wal-Mart & Home Depot they do work & detract those squirrels & their friends etc..

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