From top to bottom: leading and trailing for front rotor; leading and trailing for rear rotor.

2004, about 10,000 miles on rebuilt engine (110,000 on car), about 15,000 miles on the plugs. Premixing with Idemitsu.

Pulled them because I was getting some knocking (and P0300/P0302 codes) at 7500 rpm in 3rd gear

 

They look about as expected for 15k of cold starts, city driving/traffic, but you probably want to wind it out more often or get it out on a track.

 

Synthetic or conventional oil?

 

the knocking/error codes have been preventing this

 

Possible causes...Clogged cat? Oil in the intake? Old ignition coils? Poor cold air intake?

 

synthetic (redline)

 

on third cat, so always a possibility
coils get rotated regularly (10-15k miles)
cold air intake is AEM with the filter in front of the radiator

 

oem or aftermarket? the am ones usually dont hold up to rotary heat. either way i would get a quality midpipe, pick up a few ponies and wont be killing/choking your engine. if you replaced the oem cat 3x you could have bought 4 used 8s lol

 

OEM ones. I tried a used OEM one, but that didn't last long, so now just buy new.

Those used 8s...would they have a running engine?