Does anybody know why the JK's have 4 catalytic converters? I read somewhere that there is a sensor between the 2 on each side. Does anybody have any information on eliminating the second of the two on each side or replacing them in general?

 

I don't know but i've been wondering the same thing...once there's a programmer out like superchips that can erase codes i'm gonna go ahead and do it anyway...

 

The check engine light will be on and depending on what OBD II monitors are allowed to run with the cat "not ready" it may actually hurt gas mileage and performance. The amount of flow gained is unnoticeable and engines do require some backpressure to function. On OBD II vehicles, removing the cats is not a good idea. Not to mention its a federal crime.

 

Depends on where you live, a cat isn't required here in Alberta, Canada...and if there's no sensor after the cat then the ecu will never know...

 

For off-road use only a Y-Pipe could easily be fabricated by a skilled exhaust tech complete with with fittings to screw in the O2 sensors. As long as the sensors are plugged into the pipes OBD II isn't able to sense whether or not there are catalytic converters present.

Combined with Banks or Gibson Headers & Exhaust + a Cold Air Intake I'm betting it would really wake up this engine.

 

Actually yes it is a federal crime in Canada according to the clean vehicles act.
I worked at environment Canada in Ottawa testing emission systems on every new car sold in Canada in 2002.
Alberta just does not have an emission inspection process. don't worry that province will be forced to catch up to the rest of green living north America that isn't destroying the future of our planet and leaving nothing for our children.

I will be sure to help by submitting a question to the premier of Ontario and to the federal environment minister and question why do some province not have to comply with Canada clean air act.

but then again one 2 stroke lawn mower run for 2 hrs pollutes as much as a dodge neon does in 6 months.

 

I'll take that bet. Throw the same setup on a JK with cat and without, you wouldn't be able to tell the difference. Except for maybe the smell of the sulfuric acid the non cat would be throwing out.

 

Removing the 2 lower cats does not turn on the Check Engine light.. Also does not improve power what so ever.. Actually you lose low end torque.. Dyno proven..

 

dyno proven by whom?

 

Your best bet for removing the O2 sensors would be to by an elimination kit. Most cost around $20 and could be modified to work on the Jeep. You could build your own, but for $20 its hardly worth it.

On a side note, you may actually hurt the performance. Not all engines perform better by removing the cats, which will reduce back pressure to some degree. You may lose torque and have an exhaust that sounds raspy and flat. If you really want to improve performance, don't waste your time or money on bolt on mods or removing the cats. Regearing will be the best bang for the buck, although still not cheap. Next would be a supercharger. I would't waste my money on the mickey mouse BS bolt on mods when looking for a boost in performance. You will likely be dissapointed.