Is the pipe from the exhaust manifold really only 2"? It looks like 2.5" I stopped by my local exhaust shop and asked about prices, I was thinking 2.5" all the way, he said there wasn't room for 2.5" pipe at the manifold. We looked today, there appears to be plenty of room on each side of the manifold.

 

Ok guys here's the deal. I took a dial caliper and measured the pipe, for my '01 360 it's 2.5" at the flange for about 3" down then it's 2" to the cat.

 

Pipes are measure by Inside Diameter. Figger the pipe wall is probably an eighth of an inch thick....

 

If they're measure by inside diameter and the outside diameter is 2" - 1/8", then you don't even have real 2" pipes, or 3" for that matter, right?

You can see where the pipe is larger at the flange 2.5" outside diameter, then molded(?) down to 2" outside diameter. Why is exhaust so friggin complicated?

 

It's probably a blown plenum gasket, a failed cat, failed oxygen sensor(s), and maybe a cracked head to boot. You can't let 'em go for long like that before the head jumps on the failure bandwagon.

 

Thanks for the suggestions I am looking for a Truck not to use as a daily driver but I dnt want to be using all my spare time working on it either.

 

Thanks for the suggestions!! I'm no NASCAR pit crew mechanic but I can tell which end of the screwdriver I need to hold on too!!!

 

Actually, pipe is measured by O.D. TUBING is measured by I.D.