What size pipes coming off the shorties?

Did you have the two pipes going into the front of the cat originally? Or was your a single in single out?

 

If you have to use a non fouler that means the cat is basically non existent. So the exhaust is basically wide open I'm thinking. All in all, I think you are expecting more from the 1.7's than they can actually provide with your setup. And I'm also thinking you have 3:55 gears in that Durango.

 

Im with Zman on this, thats a pretty wide open exhaust... That cat isnt hollowed by chance is it? If you have one you shouldnt need to do a non-fouler, or something is up, afaik.

 

2.25 off the shorties into a y then the stock 2.5 for about 2.5 feet then y'd with 2.25.

 

So you have no cat or muffler?

 

Hes not mentioned a muffler anywhere, and judging by the fact he needed to do a non-fouler I'd assume IF he has a cat, its as good as a piece of pipe...
Unless im mistaken, which is always a possibilty :P

 

My exhaust is stock, homies.


STOCK EXHAUST FTW.

 

Ok, I took the stock exhaust system, added headers in place of the manifolds, replaced the stock cat with a short on(yes it's basically no existant but it's illegal to not have one and we don't have any checks in nd) and I replaced the muffler with a straight pipe and added a Shiney chrome exhaust tip.

 

And the cat is not hollow. There's only about 5 inches of material in the cat, but it's still a cat and that's the point. I've come to a conclusion, my exhaust is too open and k&n is clearly to good

 

I once disconnected my exhaust where the y pipe met the rest of the exhaust about 4 inches after the upstream o2 and had a substantial increase in power all through the rpm range.