I'm the proud new owner of an 01 Firehawk TA with 19200 miles, and i'm getting an SES light with an 'engine misfire' code. What occurs, is that every now and then, when coasting at a low RPM, the car stutters, and if i give it more gas, it appears to run like normal. I pull the spark plugs and notice that the plugs on the driver's side all appear to have normal wear. All 4 plugs on the passenger side are black. Since i was pulling the plugs out, i went ahead and replaced them with NGK TR55's, gapped at .060 (yeah, the car is still stock, but i should have gapped them smaller anyways). After replacing the plugs, i reset the ECM, but the SES light came back on after about 15 minutes of driving, and it's still misfiring.

It may be important to note that the car was shipped to me all the way across the country, so my first thoughts are that some connector came loose in transit and is causing exactly half the engine to not have proper spark. I'm not sure as to what i should be checking though since i'm not completley familiar with the LS1 yet. I'm also linking/posting a picture of a sample of the plugs. The lighter one is what the drivers side ones look like, the darker is what the passenger side looks like
plugs

 

Just a theory, but have you check your paseenger side O2s? They may be screwy and causing a rich condition in the passenger side bank. Which may cause some knok and picked up as 'engine misfire'. Any please jump in and correct me if I am mistaken.

 

i checked to see if the o2 sensor was screwed in all the way and connected. it was. is there an electrical check i need to make too?

 

i just borrowed an OBDII scanner from a friend, and the codes i'm getting are P0300 - misfire, and P0174 - system lean, bank 2. the haynes book says 'right bank' for that system lean code. I thought that if the plugs are looking all carboned up, that meant i was running rich... unless i have my bank names confused.

 

Well if it was the MAF both banks would be lean............I'm just trying to think here. Are you running headers or standard maifolds? You need to get that forward passenger side O2 checked out, the passenger side is the right bank. This may also be causing a lean condition. Can you go to like a salvage yard and pickup 2 O2 sensors for an F-body. I would take those 2 from the salvage yard, these are just for testing. Replace the front passenger side O2 with one reset the PCM and go get scanned, still doesn't work try the other one. And if it isn't that damn O2 I'm going to point my finger at the coil packs, but thats only because I'm running out of theories.

 

theres a lot of things it could be. its hard to say.. but 1st off just for the sake of it. change that 02 i wouldnt doubt that that is ur problem. im havin the same problems with my 99 t/a

 

being that the car is still covered by the extended warranty, i decided to let the local dealership take a crack at it before i waste too much time playing with it.

They tell me that the #6 injector is bad, which is what's causing the misfire. When i asked about how a bad injector on the driver's side is causing a lean code/rich condition on the pass. side, they told me that an injector not delivering the right amount of fuel can really play games with the ECU. They said they're going to replace the injector, and see if it makes the system balance out, and if not, they will explore other avenues.

I asked them about the service bulletin about rust in the fuel rail crossmember, and they said it only applied to the 5.3 and 6.0L Gen III engines, not the 5.7L. (5.7 isnt listed on the top of the bulletin, but it does say 00-02 firebird/camaro, and VIN G, which is 5.7). if the problem doesn't get fixed, i'm going to insist that they look at the fuel rails in closer detail.

 

So after almost a week of delays, i FINALLY get my car back. to make a long saga short: the problem (according to them), is that my #6 injector was 'leaking', basically stuck wide open. they said there was no signs of rust. the injector didnt fix it, so they flushed out the fuel system. that didnt fix it, so they realize that the cat is messed up from having so much raw fuel dumped into it. they also realize that the cat being messed up, caused the O2 sensor on that side to foul. they replace the cat and o2 sensor, and now its running fine.

they still tell me that its running a little rough, most likley due to the fact that i put non standard plugs in it (NGK's). I think that's a load of crap... I think the real reason its running rough, is that in my own diagnostics, i totally reset the ECU (i didnt tell them that). so the computer was trying re-learn itself while the car was running shitty. I'm hoping it will smooth itself out after I drive it for a bit.

however, it still couldnt get a sticker because the car hasn't run it's self check yet. (basically the check the car does on itself when it tries to clear the SES light because of a gas cap not being on good, etc). the MA inspection process involves plugging into the ODBII system, and if that check hasnt been run yet, it wont process the emissions test. The guy swears that after I drive it for a tank of gas worth of miles and bring it back, that it will be all good. meanwhile, no way in hell am i going to drive my new car around with a rejection sticker on it, so I told them to just put nothing on it... lets just hope that the Mass Pike ***** wont be in the mood for busting ***** when i go on my roadtrip this weekend.

thanks to all who gave me advice, ill post again when/if i get that inspection sticker.

 

got my sticker. all seems to be good except that i did get a misfire flashing SES light when i redlined it once. perhaps thats a result of the rev limiter?

 

If you over-rev'd it.. could be bent pushrods.