TOYOTA 4RUNNER P0304 Misfire on number 4 cylinder

1997 Toyota 4Runner with 5VZ-FE V6 Engine

[@kenvanguard9144]

Hi, I have a code P0300. Changed all new correct (spark plug, plug wires, 3 new coilpack, and MAF sensor.) I still have a small misfire at idle. Love your channel! thanks.

[@slalomking]

An excellent video, Peter is now showing he’s great experience

[@psychodocter]

Thank you Peter for another great tip!

[@nightdipper5178]

Good work. Had #3 misfire on my 99 4r. #3 spark Plug had a carbon stripe across the porcelain causing the misfire under acceleration. Replaced plug, ran good, but the carbon streak and misfire returned to the #3 plug within a week. It was the TPS, once change all was good. From my research this has occured on other 3rd gens. No idea why this occurs from a bad TPS but it does, so if it's not the coil it may be the TPS. I had initially replaced the Fuel injectors but that was not the issue.

[@efil4kizum]

does this ever happen on Gen1 Tacoma with the same 5VZ engine?

[@nightdipper5178]

@@efil4kizum When I had the issue I found this solution on one of the 4runner forums. If you have a misfire and a black streak on the plug in the misfiring cylinder I would consider the TPS as a possibility, but would rule out the easy stuff first, like swapping coils to see if the problem moves with the coil.

[@ohsnapsitzjustin]

Could you explain what carbon streak is? I think I have same issue. Got misfire in cyl 1 then changed plugs and a week later when I was on the gas harder than normal cruising the check engine light came back on. Thank you!

[@nightdipper5178]

​@@ohsnapsitzjustin Pull the plug and look a the white porcelain, the black streak would connect the top and bottom metal parts, it was about 1-2mm wide. I initially did the same as you, changed the plugs and a week later the issue returned (misfire under load). You should be able to see the black streak clearly on the porcelain if you have the same issue. I've only read about it occuring on cyl#3 and it is not a common issue, but who knows.......

[@jamesdavison8263]

battling a misfire on '03 gen1 on cyl. 2 ... right behind the water pump. had an unknown leak for quite some time at the seal on the pump and was running it continually lower on water so in turn that cyl was probs cooking slowly & eventually even after fixing the issue, along w/ new radiator, & timing belt, when driving across the super hot desert in heavy winds many months later it finally threw a code and i have been battling it ever since ... only that cyl doesnt seem to get full compression so thinking it is getting some bypass somehow ... time to do a valve job (& hope that is all)

[@proudtexan5513]

Excellent diagnosis and repair, Peter!! Great job!

[@patricksalter5412]

You’re a month too late 😂. I had the same problem a month ago. Turned out to be the same issue. Thanks Peter! Even if you were late lol.

[@jimgordon2399]

Thanks Petr,you are the man!

[@williameddy7217]

Thanks so much for this Awesome video!!! Perfect

[@royunderwood7514]

Very helpful. Thank you

[@Charlie_Crown]

Nice simple fix 👌

[@miguelsalami]

Good Mechanic ❤

[@flexapex9801]

I had a misfire at takeoff, with a slight hesitation, it ended up being a coil pack

[@colton8552]

Thank you.

[@cartap22]

I had an issue like that once on my 4Runner but for me it turned out to be a fuel injector, I went to the junk yard and got some and cleaned them up and worked

[@Miles-wy1zr]

You should narrate books or go into voice acting brother. I dig your voice and phrasing. “Coo coo” lol

[@johnaustin2276]

I've had a misfire but on 3 but sometimes 4. OK so it's using antifreeze and I get a heavy antifreeze smell on initial start up. Obviously there is either a Crack in the head or a headmaster but there is non in the oil. I've had her for 6 years and about once a year I have to change the plugs and keep the reservoir to level. I go through a gallon of antifreeze in a year but not my daily driver but do drive it to work(50 miles) 3 days a week and the acational camping trip she does just fine. Probably gonna think about a engine swap in the future.

[@slalomking]

Just change the head gasket

[@akshaybhasin7185]

I have a 2007 . 4 Runner and after replacing the Spark Plug and the Coil still it shows Code P0304 and the check engine light & Low Air light both flicker

[@joedominick7517]

Petr, Toyota whisperers !!!!

[@JulioMorales-ew8sc]

I hope some advices My 99 4Runner 4cylinders not power? I replaced spark, ignition wires, air filter, spark plugs,coils,fuel filter, fuel injectors, TPS sensor,air flow meter sensor, new catalytic converter, intake manifold, not check engine light on, still not power on first gear after second gear runs fine? Recently started smell coolant eje going up hill ? Any thoughts?? Thank you!

[@craigiefconcert6493]

So because we have a misfire on only one cylinder, we know the problem is not the coil. P.s. I believe the correct term for zoom is “enhance, enhance” 😂 One possibility you didn’t mention I believe is a compression problem. Could it have also been a hole burned in an exhaust valve? Did you somehow know this wasn’t the case? If the ignition system tested as ok, would you go straight to the fuel injectors, or would you also do a leak down or compression test? How would you test the fuel injector? A noid test to see it is getting signal, and then remove it and somehow test the fuel spray pattern?

[@rondav41]

i had a number 4 misfire but when the engine warmed up, it went away and stopped misfiring.

[@jonathanratliff4780]

You mostly do not use OEM parts anymore so you my friend?

[@charlesboston1]

hello , i'm hoping you can share some thoughts of the following ; working of a 1999 4 runner with a 3.4 liter motor and a 5 speed , it has a miss , code reader says number 2 cylinder . the miss only happens when it is hot . when it is cold it runs perfectly no miss , full power . when it is hot , it has a miss and is running on 5 cylinders . changed all the coil packs and wires , nothing ( still has a miss ),swapped the coil packs around , still has the same miss . installed new plugs , still has a miss , tightened to gaps on the plugs , still has a miss on #2 ..... all the plugs are the same colour , it has a new o2 sensor . when cold , like i mentioned it runs properly . i see 2 options here , possibly the injector on #2 , but my experience with injectors has always been they aren't affected by heat like this . the other option , and the one i'm leaning towards , the valves are too tight on number 2 , and when the motor gets hot all the clearance is gone and a valve is being held open ..... the intake does have a fair amount of black residue in it , but that might be normal for a toyota ( i don't work on these very often ) .... the exhaust could be the culprit , and it is all going out the exhaust pipe . any thoughts ? am i over looking something ? thank you for your time :)

[@slalomking]

He doesn’t answer comments

[@jamesdavison8263]

same problem on an '03 taco - same engine / dt ... so far i have replaced coil/wires/injector just before heading from west to east on a multi-day drive ... was good for about 1500 miles after driving through hot desert, at a gas stop not long after dark after the air had cooled a bit, upon ignition it coded again for same. Eventually i did a compression test and found that only that cyl is the one which has lost any (about 50% +) ... so it seems i'm getting some bypass somehow ( valve or ring prob ?? )

[@michaelwelschmidt9338]

The engine still sounds noisy. Is that a pulley bearing? The 5VZFE should be Lexus quiet.

[@tunahead2976]

Agreed

[@608portraits9]

Can a bad ignition coil damage a catalytic converter due to misfire of the engine?

[@stevemccooleq]

Yes. A misfire can send unburnt fuel into the exhaust which over time can clog the CC.

[@alankasman5074]

Were are you located?

[@mattmcrae1458]

Petr's poor index finger - hard working man's hands. Not like me (paper pusher).

[@efil4kizum]

OEM wires are pricey... these are a/m wires?

[@efil4kizum]

10:21 ... Where? are these boots coming from... per my parts diagram these are NOT separate Toyota parts or what am i looking at?

[@JulioMorales-ew8sc]

I hope some advices My 99 4Runner 4cylinders not power? I replaced spark, ignition wires, air filter, spark plugs,coils,fuel filter, fuel injectors, TPS sensor,air flow meter sensor, new catalytic converter, intake manifold, not check engine light on, still not power on first gear after second gear runs fine? Recently started smell coolant eje going up hill ? Any thoughts?? Thank you!