[jimhelf]

Back again with this 06 sts
tore it down and did the timing chains, new evap valve, replaced whatever vacuum lines I could.
Original issue was misfire all cylinders.
After putting all back together still same issue (mis fire all cylinders).
Checked, rechecked, triple checked all vacuum lines and intake 100% sure she's not sucking air anywhere.
Good compression all cylinders

ECM???????????

Somebody Help Please

 

[GM_Guy]

Is the ses light on? If so, can you tell us the actual code(s) stored in the ECM?

 

[jimhelf]

changed out the PCM
Running like CRAP!!!

Codes as they come up are co281,co550,po354,356,351,352,355,353, po302

 

[taylorenos]

changed out the PCM
Running like CRAP!!!

Codes as they come up are co281,co550,po354,356,351,352,355,353, po302

Not sure about the C codes; may need to take in to stealership and get the computer calibrated. But as far as the misfires, did you try replacing spark plugs, ignition coils, or fuel injectors?

TE