I am still getting poor mileage 400km per 80 liter tank. I have the v6 vortec with the w engine. The truck runs perfect but sure sucks the gas. It Starts hot and cold with the flick of the wrist. It has a perfect smooth idle lots of power. When cruising down the hiway I am barely on the pedal.
It was worse before I did some repairs now I am stumped. The idle exhaust smells strong not like unburnt gas but like an old sixties v8. Here is what I have done: Checked for codes none found. New air filter, cap, rotor, plugs, wires. Fixed leaky vacuum lines. set timing. Replaced the o rings and CPI unit inside of intake. (ouch $708.00 dollars CDN) I removed the electronic EGR valve it seems ok it moves free and no clogging. I found the fuel tuning valve stuck and fixed it.
I would like to know how do I test the o2 sensor and egr etc. with a VOM? Is there an Eprom that might help me also?