I know I have asked this before, but I have read alot more posts and have knoticed something. Everyone who has had the similer power loss as mine has had aftermarket exhaust and when the cat is removed or gutted creating a power loss. I had a AIR pipe on there which is pinched off, im getting no torque/hp ect any ideas?(305 tbi straight pipe with hooker cat back)

Maybe a o2 sensor? theres no check engine light

 

Straight pipe, as in one? Or true duals? If so, crossover or no? Too free-flowing of an exhaust system can and may cause some power loss, and you can tear up your engine. A small amount of backpressure is needed for the "scavenging effect," which in short terms helps pull the intake valves down. It's actually more complicated than that, but I'm not getting into it unless your curious.

Ill put it this way:

A friend of mine with a 350 ran true duals, no crossover(which isnt good), 2 1/2 piping, and Cherry Bombs. I convinced him to upgrade, and he ran 2 1/4 piping, H pipe, and a raven muffler and gained about 20 horsepower.

 

What dyno machine did you use??:lala:

 

Another "gotta have back pressure" wives tale. You need flow & velocity, not backpressure for scavaging.

 

The cylinder banks have to cross somewhere in the exhaust system through like an X-pipe or something so that you will get the scavenging effect. Otherwise you WILL lose power.

 

Guess the drag cars running open headers have no clue what thet're talkin bout then?

 

Nope. I run a full system that exits in stock locations with no cc or muffler of any type.