Cheesehead

Hi all, on my 98 silerado 1/2 ton 4x4 somethings got me scratching my head. When the truck is doing around 55 to 70 mph the thing starts to chug and miss very bad, worse when it is on an incline. I have checked running fuel pressure and it is within specs. Last weekend i replaced the cap, rotor, plugs, plug wires and rail fuel filter. No change! could it be tranny related? any help on this would be appreciated, Thanks.........

chevyblues

Check the fuel pressure. Then check the catalytic converter. I had similar issue on my '95. Turned out the catalytic converter was plugged enough to cause the egr valve to act weird and made the truck feel like it was cutting out bad.

chevyblues
'95 Z71, 350 TBI, KN, Borla, Dynomax High Flow Cat
145,000

Cheesehead

Thanks chevyblues, i will check it out.