well, I got my first CEL yesterday. It was P0302, misfire on the rear rotor. My interpretation is that this is a real misfire, and not detonation. There doesn't seem to be a code for the knock sensor. Is the knock sensor only used to pull timing and not throw a CEL? My misfire happened under boost and I could feel the hesitation and AFR gage went to about 9. I am running the Denso Iridium 1 step colder plugs. I haven't pulled them out yet to check for fouling, but I bet that's what has happened. I've only had them in for about 3 weeks, though. My normal AFRs under boost are pretty consistently about 10.5, so maybe the richness accelerated the fouling of the plugs. I read somewhere that GReddy recommends gapping them down to 0.030". Seems like this would probably help. Since I haven't tuned leaner, and I am still running about 6psi max boost, should I switch back to the normal temp plugs?

Anybody have thoughts on this?


-MD

 

I got another misfire this morning when I cranked it up for the first time. Those plugs are about to come out for inspection.

-MD

 

I am still running the stock OEM plugs and they are fine. I've had the turbo in for about 3 or 4 months now. No problems with it misfiring.

 

gapping down your plugs will help with that, but you'll get a slight decrease in power. What I'm thinking about trying is the 3rd gen plugs with shims Mazsport sells for use with the Rx8. They are much harder to foul and only cost like $10 or so a piece.

 

looking at the service manual, looks like the following trip that code:

plugs, plug wires, eccentric shaft position sensor malfunction, running lean from too much air or fuel injector problem, engine coolant leakage, insufficient compression for engine malfunction or OMP pump malfunction, ECT sensor malfunction, fuel pump malfunction

 

wow, lota stuff. I should pull my codes. I've had a cel on and off since I put in the turbo, I always figured it was because I haven't gotten Greddy's newest update. I should pull them and make sure though.