check engine light.. need your input

[lostatlantis]

hey guys,

my '96 firebird recently had its check engine light on after sitting in the garage for over a month. The engine made a weird noise when I first started her up. I thought maybe carbon build-up or misfiring. Anyway, I never felt the engine running so rough, so I drove as slow as possible to advanced auto parts and had the guy scann it. This happened two weeks ago (right now I am at school), so my memory is a little fuzzy. It's 3rd or 4th piston misfire, O2 sensor slow response, and there might be one other thing that's related to the piston in question (I want to say spark plug on that piston?). The guy reset it so the light went off. He suggested using some fuel additive/cleaner (which I've never used before) and bring it back if the light shows after a week or so.

Now because of school, I didn't want to deal with the repair b/c time issues. So I left the car back home, where it's been since the OBD II scan, same condition without any fix or added mileage.

I am about to head home in two weeks. Can I get some suggestions on how to proceed? Appreciate it!

[BLLDOGG]

do you know what the code was?

[lostatlantis]

I didn't write them down. He had a handheld scanner and the screen's displayed showed the info about piston misfire and O2 sensor slow response.

This is the VERY first time the light came on for me since I got the car. By the way, it was pretty damp in SC for weeks. Maybe that has something to do with this? The garage door was closed the whole time too. Right now, I have a friend who goes by every day or so and open up the garage door to air it out.

[FunkZ]

It wouldn't surprise me that a car that sat for a month without being started was rough or had a stumble on start. It should quickly clear up though. If the problem persists then I would check plugs, wires, coil packs and O2 sensor like the scanner indicated.