So I’m new to the vq platform and I’ve been reading and researching the car a lot. I bought a 2003 Infiniti G35 coupe AT, but it has some problems. So far, I myself changed spark plugs which were still good but peace of mind replacing, (bosch) Coil packs(Duralast), vvt solenoid’s, 2 fuel injectors (aus injector), and valve covers aslong as gasket changes when I was in the engine already. When I drive at 80mph the car will start to decrease and bog(sputtering sound from exhaust) then sit there for a bit before catching again and start accelerating fine. Occasionally rough idle. I do have some codes which I’m not sure about the p1276 code as I replaced injector 1 and 2 when I changed the valve covers. After finally finishing valve covers car ran beautiful for one day then went back to bogging. Another thing that has happened twice to me is my parking gear gone blank and car won’t start. Lights on dash comes on in the on position but go to crank and nothing. I have to put it in reverse, back into park, then the gear indicator will show and start right up. Car has cold air intake, headers, full straight pipe with single exit with test pipes. I know the test pipes can cause the 02 sensors so go off but I’m not sure what to do. Definitely start by getting a oem negative battery cable which I believe is the ecm ground wire(correct me if I’m wrong please.) and also clean the maf sensor to try to help rough engine idle. Any help is appreciated as I’m getting into VQ’s, cars, at the age of 16 currently. Also the c1109 code went away and there is a c1130 code now. Car also has a 2004 ecu in it, potentially tuned before? It seems like that however can’t find any maps on the car.

 

Typically you don't want to just replace a couple of injectors unless you flow tested the entire set and made sure they're all flowing the same.

Gear indicator sounds like a shifter issue.

All those C codes looks like someone disabled the TCS/VDC system perhaps as a burnout or drift car. Possibly also why it's throwing U1001 which means one of the computers is disconnected from CANBUS.

Realtime scan the O2 sensor data to see if the B1S1 is cycling properly.

 

So this is not a ecm ground wire fix? Because after replacing the battery when it died on me, that u1001 code came up. Also how would I go about real time scanning the 02 sensors for B1S1(have no idea what that is)

 

Either use a scan tool that can do real time scanning or use an android phone, a BT adapter like the BAFX one, and the Android app Torque Pro.

EDIT: If the U1001 happened right after a battery change use the pedal dance method to clear ECM codes and see if it comes back.