I have a 2004 G35 coupe and installed an MREV2 on Nov. 4 and a Greddy EVO2 exhaust on Nov. 5. About two weeks later, my Service Engine Soon light came on. I thought maybe I just needed to reset my ECU so I tried the pedal reset method about 20 times very carefully and it didn't work so I disconnected the negative battery terminal and pumped the brakes. That turned off the Sevice Engine Soon light for a couple of days, but of course it came back on. Also, during these couple of weeks my car stalled two separate times, both while I was driving on the freeway, exiting on an off ramp while down shifting.
I went to AutoZone to use a scanner to check the error code and the code came up as P0455: EVAP Emission Control System Leak (Large).
I took my car back to Auto Innovations where I had the Greddy installed and they checked everything over and everything was in place.
I assume that the problem has to do with my EVAP control box, which was relocated to install the Greddy exhaust, and the sensors got messed up in the process. And yes, the gas cap is on tight.
Can anybody please confirm for me if it is the exhaust causing the problem? I'm just trying to narrow it down to one or the other, the Greddy or the MREV2. I don't want to have to put back both the stock intake manifold and the stock exhaust if I don't have to.
Any feedback would be greatly appreciated!

 

it's probably because of the canister you either moved, or removed. that or your gas cap isn't tight.

 

Here ya go...I extracted this for you...all your answers and troubleshooting in the PDF that matches your code...P0455

http://www.ismcentral.com/DTC

Rick

 

Thanks!!

 

I thought Mrev wasn't for 03-04's.