If you took off the cat and saw an increase in power, you're cat is getting clogged.

 

did you fix the plenum yet? im surprised it hasnt been asked yet!

 

^Kind of implied that he did since he installed HS 1.7's.

But yeah, has that been done yet?

If not, we find you and slap you.

 

This, +1

I bet its not... OP read the stickied plenum thread at the top if you havent fixed the plenum yet. Your gonna need a new cat anyways.

 

Id be willing to bet he replaced the cat cause the oe was clogged. Therefore plenum hasnt been fixed and the new cat is now getting clogged

 

I didn't just take the cat out, I disconnected all of the exhaust after the upstream o2. Stock cat was not plugged when I removed it, I was doing a lot with the exhaust I decided to get a hi flow cat. When I disconnected the exhaust it had the new cat and it's not plugged, if it was it still would be. And no, I did not replace the plenum gasket. I have a friend at school who's in my colleges precision machining program make a 1/4 inch plenum plate for me and I will be purchasing a used intake that I will be porting, hot tanking, and media blasting. I currently have 2 inches of vacuum in my crankcase, I use less than a quart of oil every three thousand miles so that's why I wasn't too concerned about it just now. It can wait a few months until I have some more time. So I'll be hiding in the Midwest if you want to come give me a slap.

 

i had a grand cherokee with same setup. put in muffler and it will throw you back in the seat on tack off. you have lost to much bottom end to notice anything. also i had select trac trasnfer case for mad burn outs at cruise nights. just to be even since it was fulltime 4wd bogs down more power. i put quiet muffler back in after 3rd warning for loud exhaust. it put the power back into the lower rpms. IMO keep k&n installed.

 

Get that plenum fixed ASAP, you realize your killing your new high flow by not right? DONT IGNORE IT!! You shouldnt be burning oil at all.... My 5.9 since plenum fix has not burned a drop.

 

Same here. I burn it externally and a tad through the valve guides.

My catch can likely catches more oil than the engine burns. lol

 

I still need to get around to making one of those lol...