shor0814

I have been getting intermittent P2176 (and 2 times B2AAA) codes and reduced power mode on my 2007 C6 Z51 and need some diagnostics advice.

A little background since these are all things I have done very recently before the problems started.

1. I installed a WOT box and tapped into the TPS wire right at the throttle, used one of those cheap crimp and blade style connectors. Had to redo it because I wasn't getting a signal to my WOT software. After re-crimping no problems
2. Installed a Cortex EBC and using the same type crimp connectors tapped into pins 48 (Tach) and 57 (VSS) on the X1 connector and 65 (TPS) on the X2 connector of the ECM. Same problem getting a good signal from the TPS so this time I switched all the ECM splices with Posi-Taps and everything seemed good.
3. Drove for 1 week with no problems.
4. Upgraded my OS to 4676 and not fully following the instructions for HP Tuners I applied my existing tune using Write Complete
5. Realizing my mistake (seeing the old OS value in the PCM) I re-flashed the 4676 OS, read it into HP Tuners and copied over just my changed values and wrote back just the calibration. Everything was good to go. and again drove for 2-3 weeks no problems.

Friday, I drove around all day in 100+ heat and on my last stop, I turned it off, and started right back up to leave the AC on for my wife and it started running rough and went into reduced power mode. Did a quick scan and got P2176 and B2AAA. Cleared the codes and tried to restart with the same issue. Let the car sit for 15 minutes and tried again with the same problem. I gave up and limped it home.

Let the car sit until Sunday and it ran just fine but I dug into it assuming I probably cut a wire in one of the TPS locations so I checked both positions and didn't see anything obvious. Posi-tapped the pedal wires just to be sure I had a good connection and then solder the PCM wire since I could reach it. After soldering and redoing the Posi Tap it started up and kept working fine. I let it idle and get hot (again 100+ in my garage) thinking I might have a heat related issue or something. Started it, restarted, idled it some more, got it hot again etc etc and it seemed fine. I buttoned up the wheel well and put the wheel back on and started it up again and threw the same code.

Did some more research and found that there is an Idle position relearn in HPTuners so I tried that and the car started fine. Again, ran it for a while and restarted numerous times I thought I had it beat so I buttoned up the dash and went to test drive and boom, threw the same code.

I am now beat. I did find a similar thread where the car was throwing the same 2 codes but only in hot weather but never saw a follow up post.

So where do I go next?
Do I cut and splice in the PCM and Throttle wires just to eliminate bad wiring?
Am I chasing after a dead end and have a throttle body going bad?

I have a scanner and Tech2Win, is there something I can do in there to scan and find the actual cause while in reduced power mode?

I could also get it in reduced power mode and check the voltage at both taps to see if one or the other is reading incorrectly.

Any help is appreciated because I am flustered.

I suppose on the bright side I can consider a new intake and TB upgrade.