DedRep

Ok so first off this is going to be a strictly off-road crawler, not going to use it for highway use. I do not worry about the restriction of the pre-cat system on the 2001, I worry about the extra sensors to go out and give me trouble. Instead of doing the whole add O2 sensor foolers and all that I had another idea. I can pick up a rolled 99 real cheap, body is destroyed, along with the fan and radiator, but everything else is salvageable. If I were to swap the ECM's between the two would that work? A little more info, the 99 is an auto trans and my 01 is a manual. Just wondering if that would be a good way to bypass the 01 system without getting a check engine light, and without putting foolers in and being stuck with one fuel/air mixture. Kind of a crazy idea, maybe someone else has tried it? Again the 01 will not be used as a highway vehicle, so as far as I know it is completely legal to modify the exhaust system to this point.

Donnie_K

not practical at all. 99's were even distributor motors weren't they?

s346k

just pull the bulb in the cluster for your cel.

Boost_Retard

Just get a dual outlet 02 simulator for your down stream 02 sensors and leave the up stream sensors in the manifolds.u will have proper fuel mixture.walker 52439 if u need a new down pipe to mate up to your 01 front pipe

salad

Elimination of factory emissions gear is banned here, legal or not.

99 PCM won't work anyway.

2000+ PCM uses the downstream O2s for setting fuel map anyway. They're not just for a CEL.

Boost_Retard

I don't agree with your fuel map comment.my 01 works great. If u the OP want to know the truth about what works without the exhaust narcs getting involved just email me

salad

You can "disagree" as much as you like, it's not an opinion. That's what's written in the factory service manual describing how the PCM operates lol. If one were to replace the O2 input with something static, it would simply run with that static value when making up the mix, and not changing as much as it should based on engine conditions in closed loop.

Boost_Retard

If it makes u feel better I will get some fuel maps for u and post them up.sometimes giving something a try is better than just reading about it lol. Who said anything about static?
but your right, my Jeep won't run worth crap lol

salad

Doesn't bother me any, just saying that's the actual spec.

Boost_Retard

Well I apologize for the snarky reply but this is a touchy subject for me.I 2 was trying to find information on the subject not that long ago and was pretty disappointed on the lack thereof. In my case it had nothing to do with high performance or lack of respect for the environment, as most any 01 owner would know, getting these things to run at crawl speed without baking and going into limp mode is a real pita