Last week I pumped gas at shell. Most of the time I go to Chevorns. A days later my CEL popped up (P01399 and P0301 once awhile) Random Misfire. I thought it was bad gas. I pumped a full tank of Chevorns gas the next few days. CEL still popped up with same code. My car is fully stock nothing done to it.

Last NOV i had the same CEL but i had a valve adjusted and it fixed the problem until NOW.

symptoms: It idles pretty low <500rpm sometimes and it wants to die when I'm at a full stop but doesnt. I clear the code but after 3 starts it will pop up again.


Things I done so far is: Change sparks plugs, switch around the coil packs, NEW MAP SENSOR (did the map wack with the old one didn't do anything)and that's about it. Same CEL.

3/4/10: I bought used Coil packs and injectors with >25K from a running s2k. Drove for about 100 miles. Same CEL

3/17/10: well, i finally took my car the a shop. They did a compression testing:
(95, 210, 215,215). My compression in cylinder 1 was really low. Then they did a leak down testing found out my exhaust valve are leaking in cylinder 1.

What they said next was to take out the head and inspect it more. I would probably need to do a valve job. They quoted me $2,000 for the job.

How much does it usually cost? I remember some people updated the valves and retainers with AP2. I'm not sure.

What should i do next? Thanks

 

Let is run longer for the P1399 temp DTC to turn into a permanent P300-304. You can't isolate coils without a specific cylinder code stored.

 

The CEL is now P0301 and P1399.

 

Swap #1 injector to #4, see if the missfire moves

 

^ I did the swap. I also even bought 4 used injectors and coil packs from a running s2k with <25K on them from a running s2k. Which didn't even do anything. Same code. It does run smoother. But same CEL P01399 and P0301.

What can I do next? Don't want to take it to honda dealer.

 

Unless its a wiring issue to the problem cylinder coil pack then I'd do a compression test then a leak down test if none of the plug,coilpack, and injector switching made a difference in the problem cylinder misfire

 

Cylinder leakdown test is next.

 

will do that and report back. Thanks.

 

surprisingly i had those codes pop up the last two days. had 300, 303, 1399. yesterday i had 300, 301, 302, 303, 304, 1399. never had any codes when i was supercharged or na vafc tuned, unusual how i got a code now, researched it yesterday and found nothing conclusive but replacing single parts at a time to isolate the problem...

 

since you already know that an exhaust valve is leaking, there isn't much left to do other than fix or replace the head?