1999 Silverado 6.0

[LowRyter]

http://www.gm-trucks.com/forums/index.php?showtopic=113976

 

Would appreciate your comments to this thread. Several issues. Poor gas mileage when towing. Flashing CE Light. Coil replacement, air filter replacement, plug and wires (wrong OE plugs).

[LowRyter]

after doing those maintenance items (coil, plugs, wires, aircleaner, Seafoam) and driving for a couple of weeks, the problem didn't go away. Took it to another shop and got a completely different diagnosis.

 

Here's the deal:

 

The EVAC problem caused water to get into the gas. Need to get EVAC & hose replaced, tank drained, and fuel rail flushed. Then examine TPS, and heater sensor. Fix & replace if required. Apparently Chevy had it covered in a service bulletin related to the fault codes.