EclecticJKU

Has anybody removed the two downstream catalytic converters? Would it annoy me w the check engine light? My reasoning; the o2 sensors are before and after the upstream cats, so the computer shouldn't be able to tell the difference. Or would it read the flow and temp difference w those downstream cats removed?

EclecticJKU

I posted this a while back, and am still interested in an informative response.

casual_style

i know friends who removed the two back pro-cats and they win more brutal noise from exhaust and less back pressure.
you ll not have problem with ''check engine'' but dont cut the o2 sensors.
i ll go for that and i ll post photos and video soon

jtphoto JK

4 cats on a 3.8??? My 2008 only has 2 cats and a muffler..
Factory muffler changed out with a pypes high tuck. Sounds nice no issues.

casual_style

Are you sure for only 2 cats? My JK 2007 2 upper cats,2 pro-cats,four o2 sensors (front of cats) and a muffler...

Earth Siege

My 2009 jkur only had 2 cats and 4 O2 sensors as well. I have the entire exhaust system on my shop floor now! (I upgraded to LS 5.3L and had all new exhaust made)

jtphoto JK

Only 2 cats , 4 - O2 sensors, one muffler. My daughters 09 is the same.

casual_style

the 2 cats from driver side


the 2 cats from passenger side

Earth Siege

Where are u located, this could be a regional emissions requirement-like california....

casual_style

Hmm... European version JK