My ECU just threw the dreaded P0300 code and I'm thinking of changing my spark plugs as a starting point. I figured it's worth a shot since the car is still running on the stockers and I've got quite a few mods. My car has a little over 16k miles on it. Which spark plugs would be good for my car's power level and what gap should I use? Thanks in advance.

 

i use NGK BPR8ES on my evo 8 and they have solved my p0300. since u have a 9 i think u have different plugs so see what 9 ppl say

 

OEM FTW. No worries about gapping, and yes it is important to ge the right gapping for your car if you're running aftermarket stuff.

 

so go oem, from mitsubishi? or are there other companies that are equivalent or better?

 

You could continue with the iridiums or you could switch to coppers... If you go to copper you need to change them very often, some poeple do it every oil change. The iridiums will last a lot longer, I went 40k on my orig plugs before I replaced them. I stuck with oe...
As far as a gap I think .020"- .024" is where the manuel says.
If you search around you should find what your looking for.
FYI, if you try to re-gap an iridium plug you could damage the electrode and the dealer will rape you for those things.

 

oem ftw!!!! i had problems with every other plug known to man lol... tested em all out and the oem worked the best... just my .02

 

oem cant go wrong