FISH22

I wasn't implying that the gap shouldn't be checked. I was just saying that the NGKs are pregapped from the manufacturer. Mainly because the way they're designed, you SHOULD NOT try to gap them yourself. I have read about damage occuring during this.

maranelloboy05

Gap was .002 in too large, I went ahead and swapped two of them so I guess next week when it decides to misfire again I'll find out if it's the plugs or not.

BlackFox

Not trying to alarm you, but the day one of my cracked retainers decided to drop a valve in my cylinder, I also had a briefly flashing CEL a couple of hours earlier...

Might be worth having your compression tested and your valve tightness checked.

Brndon

When i had a flashing cel it ended up being 2 coilpacks went out and then all 4 missfired (to what i believe caused the ECU to overcompensate and make it worse) Never rule it out until you try it. I spent days on stuff before i found out it was the easiest fix ever.

Just for precaution, check valve adjustment, Injectors, and possibly fuel. Map whack, and ecu reset.

FISH22

From what I've seen Billman post on this site, it seems AP2s tend to bend valves from over revs instead of cracking retainers like AP1s.

But I do agree that having the compression checked and checking the valve gap is a good idea.

maranelloboy05

Taking the car to Cory for a valve adjustment is on my list of to-dos, even before this misfire. I've never overrev'd this car and I've had it now for 15k miles, but I understand it can come about later on.

Is it abnormal for the car to misfire only every ~500 miles? That's what is throwing me off so much, I'd be more concerned if it was semi-constant but it's been a week to 10 days between the CEL coming on and the car showing any issues. I drive ~500 miles a week and everything seems to be fine, the CEL comes on showing a cyl 2 misfire, I clear it and then go another 500 miles with no issues.

Murphg05

My guess would be something electrical since it only happens once in a while. I would think if it were mechanical such as bent valves it would be consistently having problems... my .02

maranelloboy05

Looking like it might be burnt valves, but no real idea until after a leakdown test this week. Had the valve adjustment done this weekend and the exhaust valves were pretty tight, tighter than .008. Warm compression test after the adjustment showed 240, 210, 210, 240.

ronnuke

Update on my issue of stumbling idle and random misfires: I installed the new injectors---no joy...still the same. So I decided to return to square one and remove the brand new spark plugs and replace them and guess what......yes cylinder #2 had a bad brand new spark plug that was causing the misfire. It worked perfectly for two days then failed at idle at first then at all rpms after a week. I have installed new NGK's and it operates as per normal now. I have never had a brand new spark plug fail like that before so it threw me off the trail of the true cause of the misfire, thinking well it can't be the plugs----they are new....WRONG! HTH