I am receving a P 300 code on my '03 Evo. The code seems to rear its head at 25% throttle with the air conditioner on. I have mild modifications done that include an SAFC and AVCR. I'm keeping the boost at nearly stock levels and have leaned the fuel mixture slightly. The dealer has reflashed the computer 3 times within the last 2 years. Spark plugs and spark plug wires have been changed recently. When at partial throttle, an engine misfire will occur. I let off the throttle and the engine comes back on line. but the CEL light remains lit. Any new suggestions. Thanks.

 

I bought a creader from shiv. Fixed the problem. No more 0300.

 

If you do a 0300 misfire search you will find out any information you need related to your problem.

but basically it is most likely a harmonics issue with the transmission.

get a creader off ebay or from vishnu and leave it plugged into the obd port and it will intercept most of the codes and the ones it doesn't it will erase shortly after they appear.

 

I have exactly the same problem with a reflash by WORKS. I have no idea what to do.

 

my fault for not being clear. I have a pda that clears the code. I'm just trying to figure out why it keeps missing and runs on 2 cylinders. any idea what the cause could be for that problem? I've read through the posts and tried the suggestions offered, but the problem continues.