GMC Envoy Sometimes after starting my 2004 envoy all the dash warning lights stay on but none of the gauges read anything, I restart the engine and everything works.

SOURCE: Speedometer on 2004 GMC Envoy not working. It

There is a recall on the panel Cluster... call your dealer and have it checked out.. mention the recall... www.lemonauto.com

SOURCE: 2006 GMC Envoy XL gas gauge reads empty

The sulfur content in the fuel is contaminating the contacts of the sending unit.

Some people have had good luck with some fuel system cleaners solving this problem. The cheap stuff doesn't seem to do the job.

Not that GM isn't completely exonerated from fault but the gas stations don't do a very good job of watching what the stations sell.

SOURCE: 2007 GMC Envoy - Gas gauge showing empty and check engine light

This is a safety feature that the vehicle brings. You need to reset the E.C.U on dealership or it will keep doing it to you. It was probably caused by one single time that you did not closed the fuel cap correctly. Good luck

SOURCE: 2006 GMC Envoy XL gas gauge reads empty after

It is most likely your fuel level sending unit has gone bad. It sits inside your fuel tank to tell the fuel guage how much gas you have in the tank.

The sending unit for the gas gauge is in the fuel tank and part of the fuel pump module, it is not sold seperately. Price is around $350.00, 2 hours labor to install the part.

SOURCE: What does reduced engine power light mean

this model has what they call fly by wire.. no accelerator cable. If the computer detects a problem in the thottle system it will not allow the engine to accelerate and will show reduced power and possibly set a check engine light. The dealer usually wants to replace the throttle assembly which is very expensive and usually un nessesary.
I have had a lot of succes with just cleaning the throttle plates real good.