sonicsix

I placed the order for an APN exhaust manifold today as my stock one was cracked at the collector. Imagine that, LOL. Anyway, when I do the job of replacing the exhaust manifold, what other seals, etc should I replace at that time?

I am not having any problems with the Jeep (other than the exhaust leak) but I am a firm believer in "an ounce of prevention is worth a pound of cure". I went through my Haynes manual and it made no mention of replacing anything other than the gaskets the manifold comes with.

Thanks for any knowledge you can share...

McHank

I just did the APN swap, replaced the bolts and the studs that go into the engine block (ineedparts sell them along with the three for the manifold).

About what else to change; I cleaned out the intake and ports and made sure all the connections on the intake looked ok. Some people take the throttle body off and clean it out, but then you need a new gasket for it (I just cleaned it still attached). Also didn't take the fuel rail off, but again, some people do and then clean the injectors which will need new o-rings.

Changing the driver side motor mount is a good idea when you are doing the manifold swap, mine was pretty grim looking, change the pass side mount too but that involves taken off the oil filter adapter (a pain in the rear, couln't get mine loose with the tools I had on hand). Also changed the o2-sensor and did a reset of the PCM (+ battery cable to ground for 30 sec, back on battery, key in ignition, turn to on, headlights on, headlights off, key to off I think it was). Might want to think about putting a flex pipe on the downpipe to help prevent future breakage of the new header.

edit. Just saw that you have a '99, not sure about the o2 and resetting on that one (mine's a 94 with the odbI).

austinjoe13

I just tore mine apart yesterday (only to find that it WON'T work on a renix )
But some things that made the manifolds easier to remove are removing the intake system of course, take the power steering pump off of it's brackets and lay it aside, and work on it while its cold. Also make sure you scrape the old gasket off of both mating surfaces.
Good Luck!

austinjoe13

Remove the electric fan too

sonicsix

I have a couple of write-ups plus my Haynes manual to help me along. I'm no mechanic but I am fairly handy with tools so I don't foresee any issues. I went ahead and ordered all new mounting hardware for the manifolds as well as new seals for the injectors and fuel lines... and a new upstream O2 sensor. Once I get all this installed (minus the O2 sensor), I'll take the Jeep to a muffler shop and let them make me a new piece from the header to the CAT, one that isn't caved in like the OEM pipe. Then I'll install the new O2 sensor.

I changed my oil filter adapter o-rings last week, so getting that off again to change a motor mount won't be a big deal. Getting it off the first time was serious business, though.