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I have a 2000 Cherokee Sport 4x4.I want to add a header and remove my catalytic Converter to compliment my 40 series flowmaster. I have a 4.0 six with a k&n and homemade air intake.my engine is otherwise stock.I need to know how to fool the back o2 sensor.
1) What you are proposing is illegal under Federal law, and depending on where you live may be illegal under your state's laws.
2) IMHO we cannot advise you on this w/o becoming accessories. [Disclaimer] Anyone who does post after this is expressing his/her own opinions and is not speaking for . [/disclaimer]
3) What is it you hope to accomplish by this? The new cats are pretty much high-flow and you won't gain much (if any) performance by removing it, so why break the law and give 4-wheelers a bad name for not caring about the environment?
i have to agree with naxja i had removed mine looking for a problem and i cant wait to put it back many say its faster that no ttrue i have the same flowmaster and its loud to loud i think so stick with stock not cause the law persay but it just feel better
You have enlightened me. I withdraw my question about removimg my cat.However i would appreciate info on a header for my 2000.It seems like us 2ooo up owners have been left in the cold on performance parts.
There really isn't any point in putting a header on a 2000. Not only does it already have a tubular header (the new ones that don't crack), but that would require removing the two pre-cats - which for all the already-stated reasons, would be a bad thing, and is probably why there are no aftermarket headers. If you pulled off the cats (2 pre-cats, plus the cat - which is said to be the same as the V8 ZJ's - plenty of flow) and replaced the header you MIGHT gain 3-5 hp - if you were lucky. Just the header MIGHT give you as much as 3 hp, but probably less. It's not worth the money - especially since you'd have to have one custom built. It might not be the answer you were wanting - but basically, you already have a great exhaust.
Did you notice any gains with the 40 series? I haven't heard much talk on how restrictive the muffler is - but mine is just about crushed to death.... How loud is the 40 series delta in the cabin?
Disclaimer- this is for information purposes only. I took off my cat 93 4.0 and I did notice a little more power. But when I wanted to smog it I could not get the test pipe off to put the cat back on, so I had to pay 35.00 at a muffler shop to get it put on. And for the pre-cat "problem" summit sells a plug that you stick in the O2 plug that fools it into thinking it is still there. Again I do not condone this nor does :angel:
The latest XJ's that have the redesigned exhaust manifold with expansion joints and dual outlet pipes with precats will see little if any benefit from a header. The front half of the exhaust is pretty good on these models unlike the earlier 4.0 HO models. The front pipe joining the cat is 2.5" in diameter and much better than the crushed pipe that came with the old ones. Just install a high-flow main cat and performance muffler and you're pretty much done on the exhaust side of things.
My experience:
Headers: Jeep already installed one from the factory, I know people who have installed high dollar aftermarkets from Banks and resulted in no gains that they could even feel SOTP.
Cat conv: 00-01 XJ's use the same one for the 4.7 V8's so there is no flow issue for the I6 to even warrant an aftermarket.
Muffler: to date the ONLY restriction in the exhaust stream and a flow 40 or 50 will cure that with confirmed dyno gains.
Conclusion: Appreciate what Jeep engineers already managed to do for you. Crawl under your Jeep one time and examine your exhaust system, then go crawl under one of your buddies older XJ's and you'll see what I'm talking about.
pre cats? is that a california thing?Mine has a cast iron split manifold dumping into a 2 into 1 cross pipethat turns 2 90s and goes into the cat.word around here is that the cat is problematic. Ive got 87k miles on my rig.what problems would i run into adapting a banks tj split header and downpipe to my xj?I have decided to keep a cat on it.:angel:
Don't even think about removing the cat, The 2000's are an obd II that means they measure exaust gasses before and after the cat... so removing will tell the ecu that it is running rich aand then lean out the mixture and keep leaning till you burn up the head there are Hi flow cats out there for around $120.00 ... as far as more power cut that $50.00 POS muffler off and run a straight pipe like all the other really fast jeeps, hacked mine off and wow what a differance and it only cost me $0000.000 pretty cool, and not really that loud. No one in my little group runs mufflers... Just a thought ..-
120 bones for a hi-flow cat? Hmmm, that sucks. Get a Carsound cat off ebay. Somewhere around 30-40 bucks, the guy who sells them is cool, and they are quality pieces. Universal fit, but I didn't have any real problems. This forum is where I learned about em, days before i wouldve bought a $100+ one. Passing on the knowledge.
My 89 is straight piped. Me and a few friends got bored so we cut off the cheapo muffler. With it piped its loud and annoying as hell when it shifts into overdrive and the engine is warm. sounds like a damn fart pipe ricer is next to me. Im getting 2.5 in piping, catco hiflow cat and a single chamber flowmaster with dual 4in tips on her when i put the new motor in.
ya with the staight pipe i noticed more power(slightly) at acceleration but at highway speeds it almost feels like it bogs down and has less throttle response.
So, let me get this straight... my 2000 XJ 4.0L's only exhaust restriction is the muffler? Coolness! Was gonna replace the entire exhaust system eventually, the header, the cat as well as the muffler. Saves me a ton of moola! Thanks!
XJ Saga said:
My experience:
Headers: Jeep already installed one from the factory, I know people who have installed high dollar aftermarkets from Banks and resulted in no gains that they could even feel SOTP.
Cat conv: 00-01 XJ's use the same one for the 4.7 V8's so there is no flow issue for the I6 to even warrant an aftermarket.
Muffler: to date the ONLY restriction in the exhaust stream and a flow 40 or 50 will cure that with confirmed dyno gains.
Conclusion: Appreciate what Jeep engineers already managed to do for you. Crawl under your Jeep one time and examine your exhaust system, then go crawl under one of your buddies older XJ's and you'll see what I'm talking about.
So, let me get this straight... my 2000 XJ 4.0L's only exhaust restriction is the muffler? Coolness! Was gonna replace the entire exhaust system eventually, the header, the cat as well as the muffler. Saves me a ton of moola! Thanks!
For the most part that is correct, the muffler I can confirm as well as the headers. One guy I know is running high 14's with his 00 XJ @ Englishtown raceway with all of the bolt on's I have with the exception of a Banks header, he stated to me that he could not even feel a seat of the pants difference after the header install. The only item I can't completely vouch for 100% is the cat, I've ordered a carsound at a good price so I'll let you know. But at most it'll yield 3-4 ponies and not much more. I know it's the same cat used on V8 ZJ's, but that does'nt mean it's not a restriction. Anywho I'll advise of my results with the carsound. As for the headers, unless you have problems with your factory version I would'nt bother until years down the road when the factory may finally need replacing.
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