What are the long term problems an exhaust manifold leak can cause?
Buster, I was just about to say the same thing. I had to replace the manifold on my old 99 Sport and on the 98 Sport I've got now.But I see in your sig that you have a 97 4.0. Chances are that you have a cracked exhaust manifold, and need to swap in a new one. The 97-99's were infamous for that problem. (already replaced mine)
On the 99, I went back with the redesigned (2000+) OE manifold.
On the 98, I did put a header on it. It was alot cheaper than the OE part.
I wish I could say I felt a noticable hp gain, but I can't. If I did gain anything, it isn't enough to register on the old butt dyno.
I bet if I had it chromed before I installed it I would have gained some serious hp.
Not to mention that a bigger air filter or aftermarket air intake won't do squat for performance on a TJ engine. Such products can offer significant power gains for some cars that have restricted air intakes but the TJ's air intake has no such restriction... it breathes more than well enough to be able to provide more air than the engine can consume at wide-open-throttle and redline RPMs.I already have all kinds of foliage, dirt, and furry critters getting sucked into the stock airbox. I can't imagine what I'd have stuck to my filter if it was any bigger or exposed.
...and besides, I'm actually content having a slow, ugly TJ.