jeepersjeep

I'm going to add a Flowmaster soon and was thinking about having the whole system redone minus the catalytic converter. Just pipe and muffler.

Has anyone else done this? Will it cause the computer to mess up?

Thanks everyone!

whpony96

You will have sooooo many computer issues and the loss of back pressure will completely kill your low end torque. Not a good Idea with today's modern motors.

Zylfrax791

Its been done and documented on a thread somewhere here. It was some speed shop or something and they tried all kinds of combinations including just a straight pipe off the manifolds all the way back. As long as you weld in the threaded inserts and re-install the O2 sensors you will be fine. The computer will automatically sense less restriction and adjust accordinglly so I wouldn't get too worried about the computer at all. Combined with a CAI and a chip they had a noticeable horsepower gain. This motor doesn't make any power or torque at low rpm so you might as well free up the exhaust and then rev the sh1t out of it anyway and have fun...

nangulator

There is a way to do this and trick the 02 sensors and not set a cat efficiency code, I have done it on many 4.6 mustangs and a lot of hi-po rice burners with no cats.

RedneckJeep

I took the converter off My '04 Powerstroke and it woke the hell up and set no codes...no engine light, no nuthin.

TheonlyREDhead 2008 JK

Convertors are expensive it would be nice to not have to buy another one when mine craps out!!

Red

GoodysGotaCuda

diesel + turbo + cat/ back pressure is going to SUCK! Extreme opposite from the gutless 3.8L. I wouldn't expect to see a horsepower from losing the cats, they are too large and the 3.8L doesn't move enough volume of exhaust for them to be a real restriction..

Just my 2cents like everyone else

GoodysGotaCuda

They are covered for 8 years, 80,000miles per federal government, so you may have awhile to worry about it

spinlock

Today's modern high powered engines like our 3.8L are highly tuned, balanced and controlled by the *all mighty" PCM. I would be willing to guess that little devil won't like the reduced back pressure and it will adjust the fuel, throttle, timing or something in a way that will not make you happy.

But it's worth a try no matter what the PCM, Jeep, the dealer, and Federal Regulators say!

TAMU Jeeper

Ive read about a guy who had a shop cut out the last 2 cats since the sensors are only behind the 1st two cats, didnt throw codes that way.