02 Sensors + Cat Delete

[blacKJ]

From what I've searched and have seen from crawling under the lib theres 4 sensors. 2 in bank one, both before the respective mini cats. 2 in bank 2, both after the mini cats. To my surprise no sensors near the main converter, especially after the cat. Now correct me if im wrong but a/f ratios are only set by the upstream sensors and are then adjusted based on downstream sensor input....so being the downstream sensors are only downstream from the mini cats then nothing in the system is actually checking efficiency of the main converter then besides obviously breaking precious emissions laws, running without the main cat technically shouldn't throw any codes for bad 02 sensors...?

 

[tommudd]

Although not legal I do know of a few who have taken the rear cat off ( after 03 they did not install any back there) for off road purposes only of course p:

 

[ridenby]

No codes,been running like this for 2-3 years

 

[diyman]

My '06 (per VIN) KJ ( Cherokee built in Venezuela ) never had downstream O2 sensors, I guess purposedly...
By fumbling with my scanner, I could see that there is a trickle voltage simulated on the PCM... thus meaning that
the unit isn't programmed ( You know, firmware ) to monitor sensors' activity too strictly...

Normally PCMs should monitor the voltage vs time of sensors in order to
1) check they're not 'dead' or 'lazy'
2) unveil owner's tampering intents (ie dummy tension reference) :icon_twisted:

BTW, I once spotted unused connectors hangin' sowewhere, might regard them as 'spares'?!

Looks like Chrysler techs designed an easy to cheat unit... ( again, on purpose IMO ) which surely sets a code if cat
isn't working properly, but not if one tries to fool it into 'thinking' the latter is ok...
They don't seem too confident folks will replace their cats after all :whip:. exept maybe CA pris.. , ehm, residents.

Disclaimer : this post IS NOT intended to be an 'how to...'. also because...it might not apply to Your KJ. So don't send
the 'Seals' after me... :happy175:

 

[ridenby]

Fellow in Russia had his set up for true dual exhaust,cat delete,think he had a program or "chip" made up so no lights and proper fueling. Can not think of his screen name right now.

 

[Ry' N Jen]

Max Pain.

 

[blacKJ]

^^^ Thanks for remembering, tracked down his youtube vids i like the way both of his setups sounded.

Unfortunately I don't have the money to drop on true duals :favorites68:
But I did got the main cat chopped off today. Still have the big suitcase welded in under there for the time being till I figure out what I'm gonna go with for a muffler..