"Reduced engine power"

[kayakfish247]

hey guys. So I'm new here. I have a 2003 with a 5.3 Vin z. It's probably thw best running engine I've ever owned. But is has the dreaded p1516 p0120 p0220 which are all with the tac module throttle body and throttle pedal position. I've replace the tac, throttle body, tps on the pedal, cleaned the intake temp sensor replace the mass air sensor, and ran a ground wire from the throttle body to the ecm to tac and to the engine then to the body. Also cleaned the ground junctions at the lower driver's side body and behind the head. It still throws intermittent faults listed above while driving and goes into reduced engine power. I leave a scanner connected and clear the fault and it goes back to normal. Seems to do it alot more when it rains and it's cold outside. Lately it's been doing it at highway speeds. More often when idling. Anyone got any ideas? Pretty much only thing left is an engine harness which I believe is the issue. Thanks ahead of time.

 

[Scottydoggs]

have you replaced the pig tail pugs to everything tb related? they go bad.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum, and other members will chime in.

 

[kayakfish247]

have you replaced the pig tail pugs to everything tb related? they go bad.

Hey thanks for the reply. No but I did re-pin the connectors on the throttle body and the tac module but like I said I believe it has a wire breaking down.

 

[strutaeng]

Find a wiring diagram and back probe the pins at the ECU and run temporary wires to the TAC/throttle body. See if that makes any difference.

You will basically have another set of wires in parallel, so if there's issue on the main harness, the temporary wires will prevent the intermittent loss of signal triggering the code.

If the problem goes away, then you know where the problem lies.