This afternoon I got a CEL. The codes are P0300, P0301, P0303 and P1399, which correspond to misfiring in cylinders 1 and 3. I haven't noticed anything unusual, though; no unusual vibrations, no loss of power, no problems at idle. My only modification is that I removed the airbox lid, and that was over a week ago. However, I think I overrevved the engine last night. It was very brief; I didn't even feel the rev limiter come on. But it's the only salient piece of information that I can think of.

I've driven maybe twenty miles since I first noticed the CEL. Is it worth taking it in to the dealer, or should I wait a while longer to see if it turns off by itself?

 

how many miles do you have on the car and when was the last time you changed your plugs?

 

I got it at 55k miles and I've put a thousand on it since. The previous owner didn't replace the plugs, but he only had it for about 9k. I have no records from the two owners before him, sadly.

 

unfortunately nothing really just "goes away", swap plugs and see what happens if not go somehwere and get it taken care of

 

Got it. Should I avoid driving the car until I do that? I wouldn't expect it to make things worse, but I don't know for sure...

 

I am sure you could drive it, just dont beat on it, change the plugs as soon as you can, cheap and easy, let us know what happens

 

I feel a bit dense asking this, but... are the cylinders numbered from the front or from the back?

 

Reset the ECU. Disconnect battery. Pull 'Back up' fuse, put it back in, reconnect the battery. Test drive, let it re-learn. See what happens. Oh yeah, all that on changed sparkys.

 

front to back.