Going through routine maintence since my "Service Engine Soon" light just turned on. Ran codes, came back mis-firing multiple cylinders. I searched in the Engine DIY section, but no dice. And more FI enthusiasts are in here also.

Currently running Greddy Twins @ 10psi.

What spark plugs do you recommend, and what should I gap them to?

Anything else you recommend that would cause multiple misfire?

2003 Coupe - 35,000 Miles - Greddy Twins @ 10psi - Stock Internals.

Thanks,

 

NGK LFR6A11 Stock#3672

I gap mine around 35

 

i used to get those. I would cause my CEL to come on for about a week or two and then i wouldnt get the light on for awhile. Sent my ecu off to GTM for some "tweaking". No more misfire codes and can pass DE emissions now with no problem.

 

I use the NGK one step colder, but the misfire codes are still present, I might get a reflash someday.

 

Hmmm weird never got a CEL with these plugs.

I had a Utec and now have a Haltech.
What are you guys gaping the plugs to?

 

i didnt even regap my 1 step colder coppers. never had a misfire code at 15psi

 

I have got a misfire before, but it is not a common occurance.

 

I use heat range 6 NGK copper plugs, gap to 30. My tuner has had two VQ35 cars (1 G, 1Z) come in (that he did not work on) who both had iridium plugs break off in the motor and take out everything including the heads.

 

ouch!

 

i also have a 04 g35 coupe TT and also running the greddy kit. I have the same random cylinder misfire code that comes up but my car runs smooooooth as can be. A mechanic recently told me that the one step colder platinum plugs are the plugs to go with and to make the gap 5 thousands of an inch (.005") less than the manufacture rating. i just ordered my plugs today, and they will be here on monday.

 

Hows your timming? Your air/fuel mixture may be out of balance
http://www.aa1car.com/library/us296.htm

spark plugs..
http://www.importimageracing.com/mm5...&Store_Code=ii