Hey my 92 silverado 5.7L popped a 42 trouble code and the book says it's Electronic Spark Timing, does that mean the Module is messed up or something else? The truck is chugging at 25 mph but clears up after it gets above 30mph. I'm only getting 220 miles to the tank and I think I should be getting at least 300 or so. The truck has a new Distributor, cap , rotor , coil, plug wires (factory gm) and plugs. The truck doesn't smoke at all either so I don't think it would be valve guide or rings. Tell me what you guy's think. MAN I DON'T WANT TO GO TO THE DEALER!!!