Twice now I have gotten the P300, 301, 302 codes (multi misfire) or just the P302 code (misfire Cyl 2) and twice now while sitting in traffic my 4Runner just stalls sitting there. No warning, nothing else and starts right back up. I ordered new plugs and wires. I also have been using my remote start more often now since its cold outside. Could that be the issue or is there something I am missing?

I have noticed slight lose in mpg and hp. When it stalls, there is just a small hesitation. I do need to replace the exhaust, muffler is starting to look like swiss cheese and I am getting the rotten egg smell, which reading here tells me its the cat going.

Any info is appriciated.

Thanks
Bob

 

Wow, 68 reads and no comments....

Heres the update to my situation. Installed new Dual Prong Denso plugs and New NGK wires, cleaned the coils, MAF Sensor. Made sure everything was cleaned and tight. Everything fired up well. Used the remote start and the light came on again...no more more use of the remote start and no more light...until today.

Haven't used the remote start since I think thats part of the problem. Went to work today, ran in to get something and came out to find the Check Engine light on. Once again "P302". Cleared it and went on the day...only to find the code come back on AGAIN! The engine does seems to have a little miss or hicup in it, but nothing major. RPMs at idle are around 600-700.

Is this an injector problem or something more serious? I have also ordered a new Magnaflow Cat and Muffler to see if thats anything (well thats what I told the wife, hahah).

Thanks
Bob

 

My brother threw a P0304 one time (which is similar to yours), we followed the FSM instructions step by step. I don't know exactly what we did, but the CEL never came up again, maybe you'll have the same luck.

 

for exact direction would be easier if we had an engine to go with the truck.

I had an issue like this once and it turned out to be that the spring in the drop tube of the coil was disconnected, so I took the spring out of drop tube and stretched it out a little used a screw driver to push it back in so that it clipped in to place and the issue subsided a bit.
After messing around and throwing different things at it I remembered that I never used di-electric grease in the drop tubes. so I went to the auto store got a big tube of it for $5-$6 pulled each coil and wire, squeezed some in the drop tubes set them back on the plugs and this issue disappeared completely.

if it is not this then it may be that coil however I do not believe that on either engine that cyls 1 & 2 correlate.

every since I have been all about Di-electric on all electrical connections!! saves a headache more often than not "as long as you do not go to far overboard and get way too liberal with it"
common connections use a light coat so the metal can still make contact but does not corrode.

so I would recommend this if you have not already, and if you have or this doesn't work then I would go to injectors.

SeaFoam in the tank helps either way!!

 

I've been getting a recurring P0304 myself. Tested the plugs and the coils (didn't try the spring-stretch trick - that's next), replaced the 175K wires. Still getting it, intermittently. It happens when the truck warms up, but not consistently.

I've been told by a few different Toyota mechanics that coil failure is rare, my original wires tested well, and the plugs are new and look good besides testing out.

It definitely runs down a hole or two, so I'm on to injectors next.

The miss went away for a week when I ran some Techron through on a half-tank, but then came back again just in time to mess with me at TDS. I'm going to do some scientific method (swap injectors two at a time) and see if P0304 comes back again or if the problem migrates. Then it might be time for San Diego Carb to rebuild them.

Don't forget that your remote start feature means you're warming the truck up and so you don't notice if it's missing when it's cold, or when you only let it warm up for a minute, instead of a long time.

STICK

PS> Now that I think about it, I wasn't getting the miss on the coil side, but the wire side, so it's probably not the springs in the coils.

 

Don't forget to tune in to my show on 1170AM, 6M Saturdays - Hank Watson's Garage Hour. We bitch about Toyotas all the time.

KCBQ.com for a simulcast
garagehour.com for an unfinished website
"Garage Hour" on Facebook to be my fan.

STICK

 

If the code is 0304 then you change the 3#4 to see if it moves with the injector aka if it is the injector on #4 then wherever that injector the misfire will go. if not then it probably is either the plugs or the wires.
if you have multiples on the same coil pack the coilpack is bad if it is only bad to one it is usually connection or corrosion. simply use of a di-electric grease will prevent corrosion and the contact is repaired for cleaning contacts and making sure that the connection is firm, either by streaching a coil or crimping tighter on the clip in on the wires...
If the igniter was involved in the malfunction it would effect the same two plugs as the coil equally, Always be sure to check all checks and run all tests before spending money and end up spending that extra money and time/frustration not knowing Always refer to the FSM in the general vehicle section https://www.yotatech.com/forums/f123/

 

**UPDATE**
I replaced the #2 injector and so far, so good. Runs smoother and no codes or hesitations.

Bob

 

glad you have got some thing figured out on this and thank you for posting good progress!!
I hope this is all you need! This may indicate that you need your injectors professionally cleaned.

 

Yuppers, it wound up being the injector on Hole Four for me. i bought a used one from SD Mini Truck for a few skins, and traded that with the potentially bad one on 4. Wham, bam, thank you Liquid Wrench.

Big pump going in (left over from my STi), so we'll see what that shakes lose next.

STICK

 

Hi

Let me start by saying I am new to posting and to the forum so I apologize in advance if I post in the wrong spot or ask something that was already answered. Also I am looking for advice not so much the how to because I know my limitations.

I have a 97 SR5 V6 4runner. It’s my baby I love it I have 268K on her and want to keep her running.

My problem is this idling rough and seems to be misfiring. I brought it in to my local mechanic and they replaced two of the coils a year ago then a month ago it starts doing the same thing bring it in to a different mechanic and they replace another coil. (Do I understand correctly that there are three total on the right bank.) A week later check engine light is back on and just running rough. I don’t know what to do have not brought it back in yet.

Could this have anything to do with the timing belt or an oil leak from the cylinder covers? Any advice or suggestions would be great.

Thanks

 

Quote:

Originally Posted by Arkman84

Hi

Let me start by saying I am new to posting and to the forum so I apologize in advance if I post in the wrong spot or ask something that was already answered. Also I am looking for advice not so much the how to because I know my limitations.

I have a 97 SR5 V6 4runner. It’s my baby I love it I have 268K on her and want to keep her running.

My problem is this idling rough and seems to be misfiring. I brought it in to my local mechanic and they replaced two of the coils a year ago then a month ago it starts doing the same thing bring it in to a different mechanic and they replace another coil. (Do I understand correctly that there are three total on the right bank.) A week later check engine light is back on and just running rough. I don’t know what to do have not brought it back in yet.

Could this have anything to do with the timing belt or an oil leak from the cylinder covers? Any advice or suggestions would be great.

Thanks

first off I couldn't read it in black!!

Yes there are 3 coils.. on a V6 and 2 on a 4Cyl...
Before we can help you we need further info... Plugs installed Dual ground??, Wires what brand on both and how long ago did you last change?? next what codes are being thrown?? this issue may have nothing to do with ignition at the moment... cracked exhaust manifold?? too many ???s

 

New Dude.

Timing-belt failure means instant doom (whether it's cheap or expensive doom is decided by whether the 3.4 is an interference motor - anyone?), and an oil leak from the valve covers (I'll assume you meant that instead of cylinder covers) just means it's an old Toyota (unless it's gushing, then you should probably replace 'em.

Check the codes, test the coils, wires and plugs. Then have your mechanic pull the injectors on the misfiring cylinder and test resistance. It's a cheap way to figure if the injectors are bad, and if they are, he can replace them while he's in there. If not, you've eliminated a host of suspects and can start dreaming of expensive repairs.

STICK

 

Thanks for the quick responses sorry about the black like I said new to this.

The plugs and wires haven’t been done in three years. I don’t know what code its throwing, how do i get that information.

I want to learn how to do these things myself if I can, but I don’t want to do something that is just going to cause more damage. I am trying to learn what things is regular maintenance and what is just the vehicles age.

 

go to autozone and ask them to check your engine light with an obd2 scanner, they will tell you what codes are present... sounds like you need a tune up and are going to need to get some good NGK dual ground plugs and NGK wires....

whether the 3.4 is an interference motor - anyone? no the 3.4 is not an interference engine... all toyotas that have interference engines have chains instead of belts!

 

If i were you Arkman84--i would think about going to a beginners autoshop class at a Junior college or something.......

BUT--Time doesnt neccessitate when things need to be changed--it is usually mileage. You need a code reader for your truck and at the minimum a Chilton or Hayes Manual. Field Service Manual (FSM) is the absolute best....

AND--Last but not least--dont guess at parts--check and test sensors and parts--the whole shade tree mechanic thing is pretty much dead with the advent of computer and what not.

The 3.4 Yota motor is non-interferance

 

also--Dual ground plugs will not solve your running issues!!!!!UNLESS the original plugs are toast.

The only reason toyota used dual ground plugs is because our ignition system is a "wasted spark system"--meaning the plugs fire twice as much!!!!!

 

look here for FSM on your truck... http://ttora.com/wiki/index.php/Main_Page
and here https://www.yotatech.com/forums/f123/

Be sure to read the sticky headline and look around on both links for all available info that will help in the future!! as well as now!!

and usually when I suggest replacing the ignition parts especially after 3 Years it is to eliminate these parts first the common throw away parts they will cost less than a coil and in experience they usually solve the issue... there is a benefit to replacing them even if they do not solve the issue like better fuel mileage, and the ease of mind that is not the issue, as well as knowing where to go from there! how many miles on the plugs and wires any how??

 

There is a pretty easy read about chasing ignition and injector problems on a gen-three 4Runner on off-road.com.

STICK