slow scoob

heres my story....
cel has been on for awhile, thought it was rear 02 sensor, so i replaced that. nothing... my car will not rev past 4500-5000, definetly no vtec and can barely get out of its own way. so i take it to autozone and have them read the cel... it says cylinder 5 misfire, nothing else.

i need to know which cylinder is #5 and what i should do, im hoping that its just the plug, but i need to know which one to check.

if its not, what other causes could there be...

someone please help

slow scoob

anyone?

CLpwner

I have a 2.2 and my wires have numbers on them i.e. 1,2,3,4 to signify which cylinder is which... check the wires it may say...

Sleep_DEPRIVED_Sleeper

wat year & engine u have?

CLpwner

Its a 3.0, as I'm sure you konw...

Not sure what year...

unless he has an inline 5...

Sleep_DEPRIVED_Sleeper

never mind,of course u have a v6 to have the 5th cylinder...

Here's the diagram:

------Rear of Engine------

(1) ------ (2) ------ (3)
_
| |
|_|

(4) ------ (5) ------ (6)

------Front of Engine------

Firing order: 1-4-2-5-3-6


I suggest doing spark plugs, cap & rotor, and wires... it might solve the misfiring...

slow scoob

sorry guys, its a 97 3.0. i replaced my plugs and wires a couple of months ago, and the new ones dont give cylinder numbers, ive seen diagrams before, i just cant seem to find them now. i have already looked thru all the old topics too...

would it be a fair bet to assume its the middle cylinder, either the front or back bank?

CLpwner

umm...

Sleep_DEPRIVED_Sleeper

wat was the DTC code u got? is it P0304, P0305, or P0306? If it is one of those (most likely P0305) then send me your email address, i have a TSB that shows u how to diagnose and clear the code.

The cause could be the PCM (Powertrain Control Module) detecting a false misfire.

Take the file i'll send you and go to a trusted shop and ask them to check for you, or you can do it yourselves...

slow scoob

i wouldnt think set of 5 month old plugs and wires could go bad... i replaced the plugs with bosch platinum, the wires, cap and rotor with autozone duralast bullsh*t.... i will change it all out anyway, any other possibilities?
thanks for the help so far

slow scoob

im not sure what code it was, i had my boy take the car to autozone today, ive been at work since 6 in the morning....
sleeper--- my email is STidriver117@hotmail.com

Sleep_DEPRIVED_Sleeper

You never know when you'll get a lemon... there's always the possibility that those thing go bad... especially when they are cheaply made...

Go with NGK platinum or iridium sparks and MSD wires, the cap & rotor can be Bosch or OEM... don't go cheap with things that control the EXPLOTIONS in your engine...

slow scoob

i got your email... in the bulletin it says to use pgm tester to clear dtc, but not to pull the fuse. how do i clear dtc so i can go to step 2?

Sleep_DEPRIVED_Sleeper

rent a PGM tester from Autozone. Plug it into your OBDII (behind the ashtray), then turn it on. You may have to turn the key to On or start the engine for the PGM to read the code...there should be a menu to read the code, write down that code and follow the instructions to clear it.

Be sure to read the big lettered NOTE from the TSB i sent, don't clear the long term memory...

I don't have a PGM so everything i say is off my head, i cant guarantee accuracy. It's best you go to a shop with the TSB and ask them to diagnose/fix it for you...

slow scoob

so once i clear the code, im good to rev it up and hold it?
also, this bulletin basically means i have a faulty pcm if the test come back positive?

Sleep_DEPRIVED_Sleeper

That's correct on both questions.

slow scoob

i take it the pcm is uber expensive too

slow scoob

als, thats the box unde rmy passenger seat right?

Sleep_DEPRIVED_Sleeper

the box is under the carpeting on the passenger side. call your local dealer for the price. Don't replace it until you are sure that it's the problem. Good luck.

slow scoob

well i replaced the plugs in 5 and 6, both have spark, still nothing, tried your test sleeper and it came back that the pcm is good... ie no mil light after clearing code and revving to 4500 for 1 minute...
i found that one wire on my fron o2 sensor is cut, so i will replace that... is it possible that the front sensor has been causing all this, yet no cel for it?

Sleep_DEPRIVED_Sleeper

That might be the case . The CEL for sensor only comes on when the sensors aren't receiving data (exhaust airflow)... It's best to replace a broken O2 sensor anyways.

If you're planning to mod your car and put on headers in the future, i suggest buying a BOSCH sensor that has a longer wire. It's better to plan ahead...

slow scoob

its already got headers and a greddy cat back from an accord, no problems with the wires reaching, i just realized that i cut one when i was removing the clip by accident.... i really hope that will work... im pretty much out of ideas at this point....

btw... #5 and 6 plugs had both worked themselves slightly loose... not sure why, they were all torqued the same when i installed them..

slow scoob

and also, the back joint where the headers collect into the u pipe or whater its called was slightly loose with a minor air leak... already tightened it back down is it possible that contributed?

Sleep_DEPRIVED_Sleeper

an exhaust leak WILL cause the car to bogg down so that may be one of the reasons...

did you put some dielectric compound on the treads of the plugs? that would help locking in the treads and prevent the plugs from becoming loose...

slow scoob

yes i put permatex anti-seize on the threads.... would the leak really cause the car to go into limp mode?

Sleep_DEPRIVED_Sleeper

Exhaust leak is one of the many causes of engine boggin. Let me try to explain this:

The location of the leak in your case is before the cat, which burns up the remaining air & fuel mixture after combustion. The cat helps the car breath and exhale cleaner air... However, your engine is misfiring which means the air and fuel mixture in the chamber was not combusted completely. This extra residual mixture travels thru the exhaust piping, some leaks out (rotten egg smell), some continues to the cat. At this point, the oxygen from the outside seeps through the leaks and mix with the residual A/F, causing the cat to work extra hard to burn everything. The O2 sensor senses the fluctuation of oxygen in the cat so it tell the computer to boggs the car down so that all the extra O2 can be burned...

I don't know if you'll understand, if anything i said is wrong, feel free to correct me as i'm also learning.

slow scoob

quick update... both o2 sensors are changed, and plugs on 5 and 6... now she is throwing misfire on 3 and "manufacterer controlled ignition malfunction" so i guess the cap, rotor and wires are next... any other ideas??

Sleep_DEPRIVED_Sleeper

while you're at it, change out spark plugs together with cap, rotor, wires. Also get a grounding kit or make it yourselves... good luck with everything man...

slow scoob

thanks again man

slow scoob

a little update: it ended up being the cat, all the honeycomb was totally broken apart and apparently clogging exhaust flow in the upper range of the powerband... so when it was all said and done im out about 1600$ for a problem that was isolated to the cat.... oh well, it feels good to drive her again