Well isn't this a coincidence
Was about to start a topic along the lines of ....
If you have the compressor kit then DO gut your pre-cats.
One of mine is broken up and wedged in a bend in the downpipe.
A rolling road test showed about 30hp power loss as a result
Can't see a way to be sure it's all gutted without cutting the canisters open.
So, that's what i'll be seeing about - Open'm'up, remove contents, weld'm'shut.
Now I need to find a downpipe with good pre-cats to complete rolling road tests