Hello my name is Colin. Recently purchased 2008 G35x with 54k. I purchased vehicle through an auction. Car has a bunch of aftermarket mods. I don't really know much about the mods. I know it has some type of name brand intakes, has headers a full exhaust. aftermarket crank pulley. lowering springs. I have a check engine light that is currently on. codes are P2A03, P0430. The car runs ok, seems like it dosent want to coast(feels like engine braking all the time) RPMs bounce around alot when coming to a stop.

Looking for anyone who has had similar experiences to this. And ANY help/information would be awesome.

I am a service adviser at one of the biggest Nissan dealers in the Midwest(Rosen Nissan, Milwaukee). So if the vehicle needs to be taking to the dealer I kinda have that covered. just looking for extra information.

Hey Colin! Welcome to NICO!

Those two check engine codes that were thrown are related to the bank 2 o2 sensors on the car (the ones that are after the catalytic converters, or in your case, where the catalytic converters are supposed to be).

My bet is, since the car is so heavily modified, it is either one of two things:

1) The aftermarket exhaust has either a high-flow cat installed, or a test pipe (catless) installed, which would cause the error. This could possibly be fixed by adding a spacer to the o2 sensor to "fool" the system, or, could be fixed by reinstalling OEM catalytic converters.

2) The o2 sensors could have been damaged during installation of the aftermarket exhaust.

I would chase down further troubleshooting along those lines and see if you can yield any results.

Good luck! Keep us posted - we will be happy to further assist.