Basslicks

You're welcome. However....

Without starting a lengthy debate, this forum follows the guidelines of federal emissions standards. As such, though you may live in a state that doesn't require emissions testing, the country you live in requires that you run a catalytic converter and not tamper with factory-equipped emissions equipment. These rules are stated here.

Living in a completely inspection-free state myself (as does one of our Admins). Believe me, I get it... but I'm still bound to those rules as well.

JSJJ388

I understand completely, that is why I did not go into detail on all of my plans, dont want to cause any issues.

jessikuntz

Ok. Well I just got underneath there and im pretty sure someone has done away with the cat all together!! Nothing but pipe all the way to the end.. (which is comes out right in pront on my rear passenger tire)

Basslicks

http://performance-curve.com/catalyticconverters.aspx

I recommend the Magnaflow 4300

LibertytoCherokee

I am planning on replacing my original 4.0, in my 2000 XJ, with a 4.6L stroker from Golen Engine Services. In order to get everything taken care of in one sweep and maximize flow for the new engine, I am planning on replacing the exhaust manifold with performance headers and the catalytic converter with a performance cat. I have looked at the Gale Banks TorqueTubes. Any other suggestions for high quality performance headers and cat that will work well together and provide me with the best outcome? Any specific objections to the Gale Banks TorqueTubes? Thank you in advance for your input!

Basslicks

If you have the money, Banks or Borla is the way to go with headers. If you can't afford those (I'm assuming you can given your post, but still) there are decent options out there. Just make sure the welds look good. Lots of guys have had outstanding luck with the ebay headers and a flex pipe or two before the cat.

For a cat, I recommend the Magnaflow. The 4300 series is rated for up to 4.6L displacement IIRC. As far as mufflers, I'm partial to Flowmaster super 40, but a lot of guys swear that the Thrush Welded sound the same. Maybe they do, but I haven't heard one that does yet.

I have a cheapy Thrush Turbo on mine that sounds decent. I have no carpet in the Jeep so it cuts down on the drone drastically. I had a Dynomax Super Turbo when I originally got the Jeep, but water killed it. Straight piped it until I had the time to buy a muffler and put in it... then my wife started driving it temporarily so I put the Thrush in for her.

No4x4Yet

I blew a head gasket so the head is coming of to get freshened up. While in in there I'm thinking bout upgrading the manifold. Is it worth the upgrade on a 2000? Also I was thinking of swapping to a 96-99 header and front pipe since the 00-01 headers are so expensive. I'll add high flow cats in to keep the computer happy but will they physically fit?

Basslicks

Well... first question is, do you have a Cali emissions Jeep or a Federal Emissions Jeep? If you have the Cali Jeep, you'll have 2 exit ports on the manifold going into a pre-cat each instead of one collector going to the downpipe and into a cat.



As far as whether it's worth it or not, well, depends on what you'd call worth it, I guess. Gains on a 00 aren't very much different than earlier model XJs... you can expect about 5-10 hp... Honestly, for as much as headers cost, you might wanna just leave it alone unless yours is cracked. If you cheap out, you might be taking a chance that the replacement will crack even sooner... many have reported though, that adding in a flex joint or two relieves the stress on the collectors and keeps them from cracking.

Fit? Why wouldn't it fit? Get a header correct for your application and it will fit just fine.

No4x4Yet

The jeep is my daily. I'm mainly looking to increase the efficiency, it makes plenty of power. I have the dual cats so I didn't know if the 99 headers would fit. I figure I'll need the headers and the front pipe.

LibertytoCherokee

Thank you for your help! I definitely want to do the job right, instead of doing it twice. This is my baby and a long-term build that I will probably arrange to be buried in when I die. lol. My main motivation for doing the headers and cat now is because I want to start out on the right foot with the new engine. Thank you again!

Lucidrope2001XJ

Need help. I bought a Used 2001 Cherokee sport and the last owner cut out the muffler and cat. I am trying to find the O2 sensor for the cat that's before the muffler, but can't find any connectors or even a trace of where it might be. Looked all over the WEB and found pictures but I can't find even the connector on the underside. I don't have a check engine light. I live in Illinois and emissions is required not sure if it will pass or not. Was wondering if someone could post pics of there cat and where the plug connects to.

redstarexile

So ive never used a forum other than a reference guide. But cant find a answer to this question. I replaced my stock exhaust system with flowmaster cat and super 44 muffler. Its been 2 weeks (cat still smells) but muffler dont sound as loud as i think it should be. Dose the system have to adjust to engine (something i was told) or is there another problem? (P.s couldent get first o2 sensor out of old front pipe so check engine lights on till next years e-check

Basslicks

Efficiency... well... that's gonna be a challenging task. Not a whole lot of efficiency to be found there as the manifolds are already a sweeping tube design. Some efficiency can be found by port-matching but with minimal gains.

lots of tips and tricks can be found in this thread but you can really turn a mole hill into a mountain trying to squeeze out efficiency.

Any time! I hope to do a complete tear-down and rebuild, stroker, and a lot of other things with mine one day. Higher end headers are definitely on the to-do list, along with a full 2.5" exhaust.

The O2 sensor screws into the bung on the downpipe just after the exhaust flange. It's up between the motor block and the driver's side lower control arm.

If you're completely missing it because the PO was so big of an idiot as to completely remove all exhaust emissions controls, you can find a replacement here https://www.rockauto.com/en/moreinfo...373666&jsn=355 The bung for the o2 sensor is on the bottom of the pipe up near the forward exhaust flange.

The super 44 is a quieter muffler. If you're looking for an aggressive, louder sound, the super 40 is what you should've gone with.

No4x4Yet

[QUOTE=Basslicks;3322953]Efficiency... well... that's gonna be a challenging task. Not a whole lot of efficiency to be found there as the manifolds are already a sweeping tube design. Some efficiency can be found by port-matching but with minimal gains.

lots of tips and tricks can be found in this thread but you can really turn a mole hill into a mountain trying to squeeze out efficiency.

I'm not gonna go crazy. Just thought since it's apart I may as well do some upgrades. I'm not gonna throw thousands of dollars at it though.

Basslicks

Job 1 for you is going to be figuring out if you have California emissions or federal emissions. It will be a lot more complicated of a swap if it's Cali. I don't see any advantage of the earlier manifold versus the one you have... but I could be wrong. If you're going to swap anything into it, just upgrade it to a decent aftermarket unit.