On my front pipe coming out of the manifold there is a crimp in the pipe just after the flange before the O-2 sensor. I have been searching for a new pipe and was wondering if anyone can help me find a cheap replacement pipe. I have been told it is supposed to be there but I am not buying that it looks to me to be restricting the flow to less than 3/4 any input would be great thanks.

 

probably be easier if u get us pictures, but if its factory exhaust then its probably just the crush bend you see, but again pics would be nice so we can definitely tell

 

It's factory, even 4X2s have it.

 

Here is A try at adding a pic here

 

OK second try

 

Yup thats factory, you can find them without the dent I've heard but you still have to dent it for clearance so if it isn't broke I wouldn't waste the money.Just my 2 cents.

 

Maybe you can get a muffler shop to cut that section out an weld a replacement pipe in there, looks very restrictive to me.

 

either A) put up with it, that is factory design B) try and get a replacement pipe made without it and see if it will clear C) get a aftermarket header that replaces it, my pacesetter has 3 and 3 into one http://www.pacesetterexhaust.com/jeep.php

 

Thanks guys that is a new manifold. The engine has a weird miss at an idle so I decided to go with the timing chain next it has close to 180,000 on it and am pretty sure the timing chain is original. I ordered the new timing set yesterday. compression is even around 118 to 125 lbs within the 5% and plugs are burning clean. I get around 14 hg idle to 20 at 3,000 and cannot find any vacuum leaks and not throwing any codes I even tried another computer everything I tried sensors, grounds, computer all give the same results erratic idle after warm up cycle. I figure I would tighten up the timing and go from there. I suppose it could be the dizzy gear but the spark is clean and steady so it has to be internal/mechanical. I will keep this thread going on any results good or bad.

 

Well I put the timing chain in yesterday and was putting the belt on when I noticed the chain tension backlash plastic thing in the bucket oops looks like another gasket and another day to put that where it goes. Anyway I runs a little better but still has issues. The timing holds steady when it misses I pulled the dizzy all looks good It is pointing to air fuel mix and found a small leak in the map sensor vacuum line with little improvement. My question/s is the only sensors I havent put in new are the CPS and MAP and my understanding is the CPS is for timing does anyone know what the timing should be at an idle for the 4.0 and could the MAP be giving a false reading giving a incorrect injector pulse. If I had the money I woud just replace them both new everything else is all the cylinders are firing evenly by disconnecting the injectors one at a time I am almost posative it is a injector pulse issue but any insight would be appreciated. Oh yea I have two computers with the exact same results. tks Kim

 

Well I pulled the head today and it was leaking on the head gasket between 3 and 4. Both cylinders are all the way up at the same time but fire opposite each other that is probably why the vacuum guage was low but steady. You can still see the cross hatch on the cylinders and the head is good and flat. I am just going to lap the valves put new guide seals and gaskets and slap it back together. I dont have the money to rework it proper it is the good casting #7120 I dont believe it is cracked just a small amount of gas was pushing into the water jacketnext to where the gasket was leaking between the two cylinders. I will be happy if I get a year or two of service so I can save for a long block.