Hello all, I have recently purchased an 05 G35x with 189k miles as a second vehicle. The car ran great initially and I did some work on the exhaust and one of the driveshafts. Then as the weather turned colder the car would start and immediately stall, it would stay running after doing this dance a few times. I noticed a service engine soon light had appeared so I checked the codes with my obd2 tester. I had a code for a camshaft pos sensor on the passenger side and a p1122 and a p1128. I researched the camshaft pos sensor, ordered a Hitachi one and replaced it, and cleaned the front side of the throttle body. The problem got worse at that point, the car would not stay running at any time. I decided to replace the throttle body with a new Hitachi unit and reset the ecu. The car will start up now but won't rev over 2000 rpm. I can't reset the ecu by unplugging the battery and pumping the brakes or with the gas pedal dance method. I was able to do a idle relearn on a warm engine only after clearing the p1122 and p1128 codes with my obd2 scanner. At this point the car starting running normally, i took it for a ride and the check engine light stayed off. I let the car cool off for an hour or so and went out to move it and it started and the check engine light immediately came on and the car wouldn't rev above 2000 rpm again. It forgot everything it learned. Anyone have any ideas?? Thank you in advance

 

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Check the engine primary bonding jumper (ground wire) that goes from the right side of the timing chain cover and lands on a 2-hole lug directly below the coolant reservoir.

If that ground wire is bad the ECM would definitely be forgetting the throttle position data as well as other engine management problems.

P1122 just means "something isn't working on the throttle control circuit". Normally you would troubleshoot any other codes first.

P1128 though is almost always caused by a faulty throttle motor. There are essentially two rheostats, the give inverse values, if BOTH are shorted out then that code pops up. Another possible culprit is one of the pins on the harness or the throttle motor is bent and laying across other pins.

Unplug the harness on the throttle motor, verify you didn't accidentally bend one of the pins when reinstalling the harness.

Check/clean the engine bonding jumper.