Hey fam, I've had a p0300 code for awhile now, replaced plugs and checked the wires, cam sensor as well as the coil packs everything looks fine. I can't think of anything else to check, if you've had this problem with your evo in the past and then found out a way to resolve it I would appreciate it if you could help.

 

Disable the P0300 code routine in the ECU.

Honestly search P0300 on here you'll find threads back to when the EVO hit US shores in 2003. Read, read, read. Thats should keep you busy for a few months

 

^What he said. I had the P0300 code popping up for a while. It only misfired in 5th gear. So i took my car to Boosted Tuning and he disabled the code in my tune. Took him like 5 minutes.

 

I had this problem at one time.. I would drive the car to work and not throw a cel, on the way home it would throw the cel every time.
Turned out that the oil pump was on its way out and the engine took a poop. I dropped the pan and there was metal in the oil pick up tube. I thought it was the transmission and that needless to say was not the case.

 

I had this code when the EGR solenoid failed... the car went from running ok-like cams-like really big cames-barely holding idle... id check that too.