Reduced Engine Power

[tomloans]

I have two 2003 Tahoes. An LT and a Z71. So here is what I finally ended up doing and for my wife's Tahoe it instantly resolved the problem. My wife's Tahoe would go out every 10 miles and it would not even idle. It was crazy and this solved the problem.

The cable against the firewall had some pretty good corrosion and hence it is likely there would be corrosion behind the engine also. So first I cleaned the firewall and the connection with a brush and believe me there was limited contact because of corrosion so this is first and foremost. Then of course you have to clean and tighten the two bolts behind the engine.

The video will show you what I did.

I also uploaded some pics I found on the web so you can see what's behind the engine. You really can't take these off and put a brush to all the connections and put them back on.

Hope it helps someone under the annoyance of this nonsense, "Reduced Engine Power". See this Youtube video...

P0220, p1220, p1221, p1516, p1515, p2135

 

[tomloans]

Here is a couple of pics so you can see what it looks like behind the engine...




Also under the Drivers Side door on the chassis, there are two bolts that have ground wires attached to them. Take those off and brush the wire connections, the bolts and the chassis so you have clean connection there too. Everything should be brushed to shiny metal so you have a nice clean connection.

 

[tomloans]

Delete

 

[Tonyrodz]

I finally cleaned my connections on the driver side and added an extra ground wire. Hopefully it helped.

 

[tomloans]

Awesome. Let us all know how it goes. How is the wire by the firewall on the passenger side. I have seen this one complete disconnected from corrosion. That one you will need to bring around to the otherside firewall connection in your picture when it starts having a problem.

You must be on the east coast with all the rust.

Tom

 

[Tonyrodz]

Awesome. Let us all know how it goes. How is the wire by the firewall on the passenger side. I have seen this one complete disconnected from corrosion. That one you will need to bring around to the otherside firewall connection in your picture when it starts having a problem.

You must be on the east coast with all the rust.

Tom

Which ground strap on the passenger side? I can't picture the one you're talking about. I'm in NJ.

 

[tomloans]

This one...

 

[tomloans]

Here is another video for the passenger side ground shown directly above. This one you can reach with your hand so once you loosen it with a socket wrench you can back it out with your hand and screw it back on when ready.... Once you remove it, use a brush to the engine block. You can reach back there and do this. Then you can put the bolt back on but you can go one step further. Check it out. Not the best video but it works.

 

[tomloans]

So these grounding issues completely took care of my 2003 Z71. No issues at all. My wifes 2003 LT on the other hand came back after about 4 months. it turns out the new connection that I installed has a loose connection that sets it off. This was my doing when cutting the wires and connecting new ones for the throttle body wiring connector.

 

[Tonyrodz]

I finally cleaned my connections on the driver side and added an extra ground wire. Hopefully it helped.View attachment 222991 View attachment 222992 View attachment 222993 View attachment 222994

Still getting the reduced engine power. I think it's my tps plug that I've replaced before.