Celica Forums General Discussion General New to me 2001 Celica - Misfire issues

Good evening everyone! I am new to this forum and I just recently purchased a 2001 Toyota Celica GT, with 182k miles, two days ago for $600. I purchased this vehicle to help me keep the miles off my 2014 Tundra and to save gas money. It does has a misfire issue. The gentlemen I purchased the car from replaced the spark plugs and coil packs but it still has a misfire issue.

I read the ultimate misfire guide provided on this forum, and have done the following so far.

Cleaned the MAF sensor and unplugged the fuel injectors one by one. I also checked for vacuum leaks.

Starting from the passenger side, when I unplugged the first fuel injector, the engine idle changed. When I unhooked the second fuel injector, there was no change in engine idle, and the last two I unplugged changed engine idle.

I went to a local junkyard that had a 2001 and got some used injectors hoping for a quick fix. Well, those injectors didn't change anything. I do, however, have new injectors coming in the mail.

It could be bad fuel injector o-rings. That's what it was for me also you should try cleaning the idle air control valve in the throttle body. If it's only misifiring at idle try turning the ac on and revving a little. Hold the rpms at like 2k and see if it still misfires; if not then it's probably a dirty or bad IAC.

Thank you for the response. I bought OEM Denso fuel injectors and replaced all of them. I still have the misfire issues and finally read my codes after getting my code reader back. It's reading a P0302 for Cylinder #2 Misfire. I'm going to replace all of the ignition packs with OEM Denso packs next along with plugs. I see that the IAC valve is a pain to get to.

As far as the AC goes, I revved to 2k and held it. It would idle fine then the idle would drop like a misfire. I'll definitely check the IAC as soon as I can get a chance. I appreciate your help!

Misfire could be caused by a worn or faulty ignition coil.

Swap the coils around to find out which coils are bad and need replaced.