2009 HHR, Reduced Power, Codes in this order P0641, P0452, P0107,P651.
I’ve looked them all up, so I kinda know what they relate to, but wanted the best Advice of where to start? I have already replaced the FTP, MAP, so that wasn’t the fix. Because they still come up. Let me know your thoughts? Beggars can’t be choosy!🤷🏻*♂️

 

All of those codes indicate wires are messed up. I would start by looking at the ECM connector, especially if somebody disconnected it just before the codes popped up. Sometimes the pins push out the back or get bent.

Look at the ground connections on top of the trans near the oil filter, the wire goes to the chassis ground on the radiator support.

Look at the wire loom that goes by the EVAP purge valve bracket it can rub.

Look at the wires that go to the Throttle body and the accelerator pedal.

I am surprised that those are the only codes, there should be more.

 

Ugh, Don’t tell me there should be more! I appreciate the instructions and pic. I’ll let you know what I find. How can you tell if the ECM has been changed and is not the original OEM? The reason I ask, I bought the car used about 6 years ago and I’ve looked at the ECM recently and it looks too small for the compartment it sets down into...it doesn’t fit secure to the tabs that hold it in place.

 

Under the plastic hood in front of the fuse box should be 2 modules the larger one is the ECM the other is the TCM.

 

Seems like an open circuit problem as Don says loose connections. Check the fuse box under the hood also..