Getting Custom Exhaust - NEED ADVICE

[joefnh]

I have a 03 4.0L 4x4 that has bad cats at 130k miles. This week I will be having the cats replaced and have a custom exhaust installed.

I am currently considering the following for this mod:

-Magnaflow high flow stainless cats (200 cells as opposed to the normal 400)
-Flowmaster 50 big block muffler
-2.5" stainless tubing
-Remove the third unmonitored catalytic converter

Is this the best choice for this mod?

I was concerned that this might result in a back pressure that is too low?

Any comments would be appreciated


--Joe

 

[joefnh]

Anybody...

 

[gijoecam]

It's the weekend... Many people are out either breakin' 'em, or fixin' 'em. Things are a little slow around here on the weekends.

What makes you think the cats are bad? Don't expect to ever pass an emissions test without them...

 

[joefnh]

The cats are bad due to both downstream O2 sensor data showing little or no effectiveness even after replacing the O2 sensors, and the driver’s side cat is rattling like crazy, the internal biscuit is breaking up.



With that bit of news and the desire to upgrade my exhaust, I was looking for input this weekend as I will need to get this worked on by mid week, hopefully before failure causing a plugged exhaust somewhere on the side of the highway

Thanks for the reply, this site has been a wealth of information.

--Joe

 

[joefnh]

I should also mention that even with the new O2 sensors, I am still getting the P0420 and P0430 codes resulting in a CEL