So, kept running into issues on my 2004 Tahoe with reduced engine power and service stabitrak. Would also have issues going from a dead stop to accelerating, and I would have to let off the gas and press it again to go. Pulled codes, and it was for P0220, the pedal sensor and for P3125 throttle sensor. I replaced the entire gas pedal and throttle body and sensor with new parts. That solved the warning but occasionally would get the hesitation and a grinding noise if I didn't turn off traction control. Never did it with traction control turned off. Anyways, went to drive today and it's throwing the same codes as before, on parts 2 months old or so. Cleared the codes with my scanner and it's running just fine. I've read OnStar can cause this but my truck isn't equiped with OnStar. Where should I look next? It is very frustrating. Has never done it while driving, always when I turn it on. Thank you in advance.

 

All GM vehicles have 4 code families. Most basic scan tools only check the P codes. There are U,C and B codes also that need to be scanned. That's where ABS codes live for example along with the many other onboard systems. Shops and dealers always scan all 4 code families as a first step.