Hello

I recently swaped heads with another lsj because mine cracked ...I have a...
2007 cobalt ss s/c
lsj 2.0l
180xxx mi
had multiple problems but manged to reslsove them all except this...
A week after getting it to start and running g fine, the gas gauge stared falling to empty then go back up over and over and if I drove it the other gauges would go out them come back also...troubleshooted the gmlan high and found a unt pin in the after market radio harness...solved...while trouble shooting I disconnected connector 201 next to the. Steering colum...after reconnecting, my boost gauge stayes maxed to the right and I can get the motor to turn on ur it runs really rough and when it did scan showed a misfire, and multiple sensor problems including map and iat, I check and gmlan high is still good 60 ohm res. And fluctuating between 2.4 and 2.5. However gmlan low and serial 2 are both dead at 0 or .1 volts. Pin 1 and 2 on dlc respectfully. I have been all over this and I am exhausted check all the fuses checked continuity between pin 16 on c1 ecu and pin 2 on dlc , it's good. Also probably worth mentioning pin 1 was getting voltage and connecting to scam tool yesterday now it's not at all...same deal with he splice. They were at .30-.50 now there all 0 🤯🤧. Idk even where to go from here right now any help would really be appreciated . Thank you