Hey guys, I'm kind of an exhaust retard... a while back my dodge started losing GOBS of power so i did all the normal things that i could think of such as replacing spark plugs, new cap and rotor, tps sensor, map sensor... the works. well, finally i thought that maybe... just maybe something was blocking the exhaust, so i unbolted the exhaust at the flanges (where it connects just above the cat) and holy crap it ran fine (but loud). so then i sawed my cat off and the honeycomb was completely melted shut. so being the redneck that i am i just ran a piece of pipe through the cat and completely busted out the honeycomb, then blew air through it to get out all the little pieces left in there out. then i welded the cat back into place so that if my truck gets inspected by the cops, it at least LOOKS like i have a cat. way before all that happened i got a 3" cat back exhaust job done with a super 40 series flowmaster installed. my question is, will not having a cat screw with the power potential of my truck? i replaced both the O2 sensors after all this mayhem, and it threw a code for a while saying that my O2 sensor after the cat wasnt working right or whatever. that code finally stopped coming up, but should i go to the junkyard and pull a good cat off a truck or just leave it? i'm on an extremely tight budget cause i just got out of the army and i dont have a job yet... damn economy, so i cant buy a high flow expensive cat. thanks guys!

 

Magnaflow highflow ran me around $78 for 3" in/out at a local store. Summit carry's them. You would probably benifit from an o2 simulator for the rear sensor if you do decide to leave your cat gutted and not install a highflow. If they do the sniffer test for inspection I would put a cat back on it. If not, then its up to you.

 

What I really want to know is because i have a gutted cat is it going to hurt my truck's power?

 

No cat and 3" exhaust will rob the lower end of some power. But probably not enough to worry about.

 

A 3" single is ok but 2.5" duals is about max on a 360. The gutted cat isn't hurting you as long as you don't have have your pipe probed by the state. Save your money until you can afford it. Then, if you feel you really WANT to comply, get a Magnaflow.

 

ok if its not gonna rob me of a ton of power i'm not gonna worry about it. in the county i live in they dont require emissions so screw it i'm not payin the money for a new cat. thanks guys.

 

I would still suggest getting an o2 sim or the non-fouler trick. Might make your truck run a little better.

 

I see more probs coming than it's worth.

 

You can find the "plans" to build your own O2 sim online, just google. That'll help you from throwing codes and get the truck to run smoothly and not waste gas.

You need a real O2 sensor up front and the sim in the back will tell the PCM the cat is REALLY efficient. The O2 sim I run tells my PCM the Cat is 99.2% efficient

 

without the front cat plugged in youre going to run rich..just either get a high flow cat as stated,,or drill and tap a hole and do the spark plug fouler idea...my 02