My 2005 XC90 just received a new transmission, radiator, and all new lines from Volvo "goodwill." Additionally, the fuel pump was replaced due to recall. On the way home from the dealership the Check Engine light came on, along with the message, "Engine System Service Required."

I returned it to the dealership and they retrieved these codes:

ECM-120C AIR MASS-SIGNAL TOO HIGH
ECM-120D AIR MASS-SIGNAL TOO LOW
ECM-1210 MASS AIR FLOW SENSOR FLOW TOO HIGH
ECM-121B MASS AIR FLOW SENSOR FLOW TOO LOW
ECM 21ED LONG TERM FUEL TRIM BANK 1 SIGNAL TOO LOW
ECM 21FD LONG TERM FUEL TRIM BANK 2 SIGNAL TOO LOW
ECM 3100 MISFIRE AT LEAST ONE CYLINDER – START UP
ECM 3210 MISFIRE CYLINDER 1 – START UP
ECM 3230 MISFIRE CYLINDER 3 – START UP

They scheduled an appointment to return for further diagnostics next Tuesday (after the holiday.) The car began to drive markedly worse on the way back to my house, stalling, etc. Any help/insight would be greatly appreciated.

Thanks

 

maf plug, not plugged in or broken. wire pinched. i would check in the area around the driver side headlamp. check if the wires are all ok.