97 chevy 305chugging

[Rumor Has it!]

My 97chevy silverado chuggs about 55mph I changed a fuel filter and its still doing it I put it on the scanner and no yranny codes or anything has came up soo I changed the plugs and wires still with no luck I'm stumped.. what could it be?

[RIP_K52007]

did you change the cap and rotor?   EGR valve is another one too look at.. could be alot of things tho. Do you still have a coverter on the exhaust?

[Rumor Has it!]

No I havnt.. ok ill change all tht.. n no I just got straight pipes..

[Eroq]

No codes?  If its straight piped it should be throwing catalyst efficiency  codes....   probably why its running crappy

These engines NEED cats to run right, not to mention you dont lose any power from them

[Rumor Has it!]

Well it had cat codes but I didn't think thg it would be chugging.. like it is. Idk its weird.

[Eroq]

Yup.... computer calculates the readings before, and after  the cats to partially determine how much fuel to use to get the most efficent burn...   pull your plugs, i bet theyre fouled out.... running way too rich.   Friend of mines did that when we pulled the cat off... poured fuel out of the exhaust and got like 2mpg

Fixes.... put cats on it...   o2 simulators,  reflash computer,  sparkplug nonfouler trick,,

I suggest putting cats back on it...