So i knew i had a leak somewhere but was having trouble seeing it and ended up searching the forum. So i checked the infamous collector and sure as sh*** it looks like its gonna crumble on me any day now. Im gonna try and have and APN replacement here by this weekend so i can tackle the job and get back to enjoying my jeep. I read 91jeepman's write up which is awsome but was wondering if anyone else had some helpful tips they could share. Thanks in advance.

 

Good Luck. This was my first ever automechanical project, and it was funnn. Swivel head gear wrenches are great, and a lonng 14mm wrench for the centre manifold bolt...

Also, check closely for clearance between the header and the intake or you'll be taking it off again to file aluminum, like I did. And torque it well, or it will start whistling after 8 months, like mine is.

It is cheap tho!

 

X2 on the intake and exhaust manifold clearance. I've had three different apn headers and each one was bent slightly different. The first one didn't rub anywhere the second one contacted the webbing between the front part of the intake manifold the third one contacted the webbing between the rear part of the intake manifold. I just cut the webbing out from between the intake runners.

 

Well i have a whole new problem now. Went to order the apn header and it is no longer california legal. I guess it was questionable for a while and the smog ***** ruled against it. So now im trying to decide between an oem garbage replacement or a 3 to 600 dollar performance header. Unless someone has found a decent lower priced california replacement out there.

 

Get the Dorman one with the expansion joints. No problems in years for me. This type was used on the grand Cherokees with the 4.0 In later years I believe.

 

And be aware of this:

 

I don't see how it couldn't be CA legal. As long as it has the bung for your o2 sensor I wouldn't even worry about it. Not to mention no one is going to be able to tell once it's in there. Can't think of any way it would cause a problem

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Edit
Never mind I just looked at the CA set up.... Jesus christ 4 o2 sensors and collectors in the header. Not quite the same

 

I probably should have asked what year your jeep is... if it's pre 97 and only has one up stream o2 run the apn header... otherwise just get a stock replacement.

 

The problem with it is it isnt registered with the California Air Resources Board. Emissions wise its fine. And its a 91. Gotta put that in my signature...but i might just get it anyway and slap it on.

 

i put a cheap replacement (from amazon) on to replace my cracked one. a year later, the thing still looks like new--the new one has the expansion joints. I did clean and paint with header paint before installing.--also, i ditched the gasket that was included and bought a fel-pro gasket.

 

I run this one from Ebay. Works perfectly. Idk the "California Legal" status. It went on with zero issues. Didn't even have to grind the intake
http://www.ebay.com/itm/STAINLESS-STEEL-4-1-RACING-HEADER-EXHAUST-91-99-JEEP-WRANGLER-CHEROKEE-TJ-YJ-XJ-/150751275246?hash=item231979e8ee&vxp=mtr

 

Thank you everyone for all the input and advice. Got everything in without a hitch. (If you dont count the vacuum lines that turned to dust in my hands. Haha.) This is an awesome forum with knowledgeable people willing to share. Makes me wanna buy another XJ.