When you go WOT isn't the o2 out of the loop? Anyways I will post what I come up with . Thanks

 

Here are the criteria for tripping the P0300:

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http://www.lilevo.com/mirage/EVO%208...05500C-13A.pdf



-Jamie

 

Common issues I found to cause the P0300 are too cold of a spark plug heat range, too tight of a spark plug gap, poor quality air intake pipe on a MAF causing irregular low airflow turbulence and erratic fueling, and bad coils/wires.

-Jamie

 

Nice. The win is coming out in this thread for sure.

 

You are correct.

 

What are the spark plugs gaped to?
I would also suggest a retune for the S3s, especially after going from HKS 272

 

The car was retuned for the s3's, when it doesn't miss it pulls very strong. I think it may be ignition related but wont know until it gets figured out. I'm running NGK BR8ES gapped to .018, I made them a little tighter because I was running them at .022 and thought maybe they were blowing out. Do you think the BR8ES are too cold and what gap do you recommend?

 

.022" shouldn't have any blowout issues at your level, even on stock coils. 8's at .018" can definitely have some misfiring at idle and light cruise at times. More so with stock coils than with the non-CDI setup you have.

-Jamie

 

I had this CEL pop up 4 times over 4 years of driving my 03. 2 different shops said it wasn't anything to worry about, happened a couple times when I got on the car getting on the highway and a few from normal driving in 2nd-3rd. Only thing I never played with trying to fix this issue was the injectors. weird

 

.022-.024 should be fine. I would check every wire, connector,ground point possible, especially if it was touched when installing the cams. Ive seen a few wires pull out of clips for the coils and make loose connections that cause random issues.

 

and i would recommend a 7 heat range NGK plug

 

I use to run BR7ES 's , you really think I would be ok on the 7 heat range? It would be less prone to fouling . Thanks

 

I wouldnt say that GSC specifically causes the P0300. That code has been an issue in ALL Mitsubishis since 1995 and typically never has anything do with a real misfire. If you are actually getting misfires that you can feel, like hiccups in the car, and it throws the code that is different. Just getting the P0300 means nothing.

Get the car retuned for the cams (it definitely needs it), check for boost leaks, then turn it off and be done with it.

 

Right but you WILL pay attention to it when it starts affecting the "act right" of your car and it becomes no fun to drive.

 

He is talking about his car being dead rich, hasnt been tuned, and now has a code. The code doesnt make the car run crappy, its the other stuff that is doing that and it happens to throw the code as a result. The cause and effect are out of order here.