i thought you forced indution guys would want to know this, since my rebuilt moter everytime i drive the car i got the p300 code (random misfire in mutiple cylinder) really no big deal i have a scanner and jsut cleared the code, cause the car was running fine. i know alot of you guys using the emanage get this code and even more w/ rebuilt moters. anyways 2 weeks ago i replaced my hks hi-power exhaust with a custom dual 3" exhaust. ever since the swap the code has never came back, (keep in mind i would get the code everday before the swap). any ideas on whats going on?

 

Search for the code, this has been discussed alot. Here is one link:

https://my350z.com/forum/forced-induction/142187-ses-p0300-code.html

 

yeah i know, i thought the other people would find it interesting that my code went away when i change my exhaust.

 

Is the new exhaust just a cat-back?

 

Paul, same thing happened with a couple of cars we did. The misfire code can be caused by a ton of different things. However, with higher boost cars, and restrictive exhuast, the extreme backpressure and thermal load on the motor can cause a subtle misfire. Switching to a free flowing true dual 3 inch made the code go away.

Backpressure is a serious enemy of safe FI operation.

 

the new system is 3" right after the greddy downpipe.