Best header for older 630 head in a 2000xj

[xjrob]

Hi folks, I was wondering if there is an after market header that will work when using a 96 630 head in a 2000xj. The newer 331 heads had the higher and smaller exports. The exhaust manifolds had the twin down tubes. On e-bay there are headers that have the dual outlets and have a 1.5" diameter tubing from the flange back to the collector, has anyone tried these? If so what was the result. I guess I'm tight and do not want to buy an earlier header plus have the exhaust reworked, unless that is the only way . Thanks guys for all of the great information that you post.

[Cybershot]

Hi folks, I was wondering if there is an after market header that will work when using a 96 630 head in a 2000xj. The newer 331 heads had the higher and smaller exports. The exhaust manifolds had the twin down tubes. On e-bay there are headers that have the dual outlets and have a 1.5" diameter tubing from the flange back to the collector, has anyone tried these? If so what was the result. I guess I'm tight and do not want to buy an earlier header plus have the exhaust reworked, unless that is the only way . Thanks guys for all of the great information that you post.

I have / had the same problem. I used the 0630 Head on my 2001 XJ. I know the the 2001 exhaust manifold might not line up with the 0630 head but tryed it. The screw holes are fitting but the ports / headerpipes are not. Also the gasket was leaking. I bought an 1999 header and a pice of the downpipe (connection between 1999 and 2001 are not the same. No chance without welding) and try now to fix them together. Most propperly I can tell you more tomorrow. It shall fit and it is for sure an low budget solution and the costum made headers are the better option.

[Cybershot]

So, took tje old header out yesterday and tryed to figer out how to replace ith with the 1999 header. First problem is thet the 2001er has 2 pre cat sensors and 2 post cat sensors. The 1999 has NO sensors

Rest seams to fit and the routing of the pipe is working as well. I will place the pre cat sesors in the 1999 headers, because ther are needed. The post cat senors I will not fit, 'cause the just measure the efficency of the cats, which I don't need to care in the UAE. This will give me most propperly an "check engine" light, which I am not happy with, but have no other choise! Here is no aftermarked header available and a costum header will take 2 weeks. I am waiting till my next vacation and will replace it then with an costum made header!

[Cybershot]

Here the 2001 header with the 4 sensors. 2 pre cat and 2 post cat


Here I will add the 2 pre cat sensors in the 1999



Also you can see that the flanges are not fitting from the measurment and need to adjusted.

[SilverXJ]

Ugh.. you have the cali emissions package.

I have heard that the aftermarket headers for the 00+ vehicles have larger ports that fit over the earlier heads very well. I haven't confirmed this though.

[gradon]

http://www.cliffordperformance.net/Merc ... _Code=J258
I will never buy an XJ with the cali-package--what a mess.

[Cybershot]

http://www.cliffordperformance.net/Merc ... _Code=J258
I will never buy an XJ with the cali-package--what a mess.

Mess? Hmmmm you have to see my entire build up. This is not an big deal. I keep this till my costum made headers are ready to build in. What's the problem? I even could have kept the 2001 headers, just did not like the small exhaust ports on my nicely ported head.

[SilverXJ]

http://www.cliffordperformance.net/Merc ... _Code=J258
I will never buy an XJ with the cali-package--what a mess.

I don't think that description is correct. It won't be a direct bolt in for the 00+ system. It is too long. Or really any stock exhaust system. And if it has precats you would need to relocate those.

What's the problem? I even could have kept the 2001 headers, just did not like the small exhaust ports on my nicely ported head.

The 2001 manifold would have leaked on an earlier head.

[gradon]

I'm not saying your build is a mess. I would never want to deal with 4 o2 sensors and pre-cats that bake an already hot intake manifold.

[Cybershot]

I'm not saying your build is a mess. I would never want to deal with 4 o2 sensors and pre-cats that bake an already hot intake manifold.

Ok, now I got it. You think the pre cats are greating to much heat in the engine bay. Well right and the ports / pipes are very small. That's why I want to convert my 2001 XJ to an 1999 exhaust system.

About the O2 sensores. I will fit the pre cat O2 sensores as mentioned in the pic above and about the post cat sensores I am now thinking of using O2 sensor simulators, to have no "check engine" light in the dash board. In my downpipe are no holes for the post cat sensores, so I want to use some simulatores as stand alone system, without the O2 senosres like these here.



Found here: http://www.afterthoughtsauto.com/o2sim.html

Which type is my O2 sensor? Anybody has expiriance with that??

[gradon]

I agree with keeping the pre-cat sensors, which control the fuel trims, and to use 2 simulators for the after cat sensors, which will keep the CEL off if they were just disco'd. I don't know which style connector yours has, so you'll have to do some research(look for pics of replacement after-cat sensors for your year Jeep). Over on NAXJA, there are countless complaints of hard-starts and heat-soak issues that I feel are due to those precats. When the vehicle is shut off, the engine bay is so hot that the gas inside the injectors boils and creates air-pockets(usually the middle injectors above the precats, as seen from the p0303 and p0304 misfires), which then take time to clear out on the next restart. Jeep's service bulletin was to put heat shields on the injectors, but that is a bandaid--the problem is the pre-cats.

[Cybershot]

Thanks, do you know any other source for the "plug type" (as shown in the pic above) O2 simulators? I am not sure the on I posted above are fitting to my Jeep XJ 2001 and till now they don't answer my mails.


EDIT: found this here: http://www.magnumtuning.com/en/product_ ... eliminator

[SilverXJ]

I have O2 sims by Casper. They work well. However you can no longer get them because the EPA sued Caspers.

I have talked to someone at www.thefastman.com in the past and they said they had O2 sims. As well as this guy Ryan Weber [[email protected]]

Also, your connector type is not pictured above. Its round.

[gradon]

Fastman is who I had bore my TB to 62mm w/ half-shaft--good peeps.

[Cybershot]

You know what is really funny? I did the headers exactly as mentioned above in the pictures and due to the point that I don't have the "o2sims" I left the cable just hanging in the engine bay ( to fix the O2 sims later)and guess what........... Nothing happen! No CEL and the AFR is perfect. The Stroker runs as smooths as it could be.