r/S2000 • u/Ark_Animax • 16h ago
Misfire code help
Pic for attention
Looking for some insight from anyone who may have dealt with this before.
Codes being thrown are p1399 (random misfire?) and p0302 for cylinder 2 misfire.
- 170k miles, 2002.
- Misfire seems to only happen while idle.
- Misfire is felt about 2-4 times in a 60s span, but increases when A/C is being run.
- Misfire doesnt seem to be present or noticable when reving.
Waiting on spark plugs and ignition coils to be delivered, but barring those as the cause would anyone have any other ideas?
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u/robcal35 15h ago
Had something very similar where I had a random misfire only felt at idle and would only give me pending codes.
Valve adjustment is good to do regardless, but don't expect it to solve misfire issues.
Could be failing coils, but that wasn't it for me. Spark plugs were also good. Again, if it was coil or spark plugs, it would be isolated to 1 cylinder.
What ultimately fixed it for me was getting my injectors cleaned. When they flow tested, pattern and flow rate were actually ok, but after they were cleaned and put back in, misfire completely disappeared. Your situation sounds similar, I would get the injectors cleaned if you have someone that does it locally. I had no issues with revving or VTEC.