2003 Chevrolet Silverado

Engine Performance problem
2003 Chevy Silverado V8 Four Wheel Drive Automatic 90,800 miles

The truck starts fine but when I try to punch it down in the city or try and take it on the highway the truck is really sluggish and the engine light comes on. I had it analyzed and it said check Mass Air Flow sensor as well as irregular cylinder fire. I started by replacing the spark plugs and wires then I replaced the fuel filter and finally the MAF sensor. What next? Could it be the fuel pressure regulator? Thanks, Gary
January 30, 2010.

Hi gbob37, Welcome to 2carpros and TY for the donation

Check the fuel pressure to rule out the fuel pressure regulator and fuel pump. The pressure should be 55-62psi

Misfiring can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.

Jan 30, 2010.
Raz, Thanks for the response. Took the truck to our local Muffler Man for a complete readout and it turned out that one catalytic converter was plugged. $200 to replace the bad one or $600 for complete direct fit. Should have checked on line first. Found an EASTERN direct fit for $325 including shipping from Discount Catalytic Converters. After replacing the fuel filter, plugs and wires then the MAF sensor I got fed up and told them to put the direct fit unit on. Runs like a raped ape now! Tell others about my journey and also tell them about Discount Cat Converters. Thanks Again for Your Help, Gary

Feb 2, 2010.
TY very much for coming back letting us know that actual fix for this problem-God bless and Take care

Feb 2, 2010.