I'm new to this site so first of all any and all help is greatly appreciated. The thing is i have a 200 GMC Sierra Classic SLE 5.3l vortec. My truck is bogging like I have no power and it has to catch up to it's self.Almost like a car with a carburetor that's flooding when you floor it but ok when you let up on the gas.Also pulling or A/C on its a little worse.well that's what my truck is doing.I was told it would need a tune up and might fix the problem or might be plugged catalytic converter.also no service engine light on.took it to a shop and done tune up..no help..3 different shops said I need the catalytic converters changed. So i put new stainless steel magnaflow catalytic converters on..no help. Anyone know what the problem might be because everyone I've talked to said it's what I've done already.
