99 alero has check engine soon engine misfire light again
I was on the way to a service station to change my alternator and some lights lit up on my 1999 olds alero 6 cylinder automatic vehicle.
The mechanic at a service station replaced the alternator but noted you may want to check the check engine soon light at another mechanic. He says he reset it. But it turned on as I pulled out. I don't know why he couldn't check it out more.
The electrical system light went out but the check engine soon light remains. He says the code is 303 engine misfire cylinder 3.
I had another mechanic check out this light last april after some repairs including the cleaning of fuel injectors. I took it to that mechanic, last april, and he said he could find nothing wrong and reset the light and it stayed off until now. They thought it was from the cleaning of the injectors. But I didn't have that work done this time. I don't know how to reset the check engine light or how to deal with this as I had the fuel injectors cleaned last april. Could something else be wrong? How do you reset the light on this model if that is the answer? And, what if it comes back on?
Thanks for your help. I appreciate it.
Movielover from seattle area
Thank you very much for your detailed reply.