02-09 Vortec 4.2L I-6 Engine and Drivetrain
I got the code P1221 a while back. I cleaned the TB and reset the PCM. I drove maybe 30 minutes. I rarely drive this more than 15 minutes at a time as it is not my daily driver. Things were good for a out 4 or 5 months. Then same code.
I bought a new TB and replaced the old. Reset everything...