what size are the exhaust manifold bolts on a 2001 xj? and does anyone know the best way to tighten the bolts under the headers? i can get the top bolts and couple of the bottom ones but there are 2 that suck

 

i have a 2001 XJ with the 4.0L, i need a full exhaust system. what is the best option for sound and performance?

 

[QUOTE=SandGhostXJ;3604364]i have a 2001 XJ with the 4.0L, i need a full exhaust system. what is the best option for sound and performance?[

 

You won't gain any performance with any exhaust on a 4.0L. Buy whatever you like the sound of. I love the sound of my Thrush welded muffler. Deep, but not annoying and no drone.

 

You might look at my build thread posts number 30 and 32. That is for a '91 XJ so the part numbers will be a different but similar part families are available for the '00 and '01.

https://www.cherokeeforum.com/f46/19...256001/index3/

 

A little late to the party, but my old 97 XJ had a glasspack muffler and then I did the dynomax cat back. I remember noticing a slight bit more response off the line when I went from stock to the glasspack and a little more response when I went from that to the dynomax. I was actually surprised because the glasspack is obviously completely a straight through design. Cruising was nicer with the dynomax too. It had a little noise, but it wasn't obnoxious if I recall. Probably didn't gain power either way, but there was a seat of the pants feel when you just blipped the throttle to move that seemed better after going away from the factory muffler.

 

Anyone know where to purchase an EGR bung? Part Number? Etc.? I want to install the HO exhaust manifold on my 89 Renix, and need to install the EGR tube to pass smog test.
Much obliged,
AVjeeper

 

You could try eBay or Amazon they're pretty standard it should be easy to locate. I purchased one a few years ago for my dirt bike. Another option is to go to the junkyard and just cut one out of the exhaust and weld that in.

 

The exhaust pipe running from the first cat to the second is directly below the passenger floor board. In an effort to cut down on heat transfer, I spaced the shield down from the floor board with a plumbing stop from the hardware store down and bent it to shape:

Installed:


Note: care must be taken in choosing a screw length - carpet and underlayment should not be penetrated by a screw. I spaced the screw with washers to assure enough bite without causing this problem.

 

Cut it off the old exhaust

 

The only set of headers I found for my 98 ZJ is a thousand dollars. Has anyone else had any luck? Why is the selection so small?

 

https://www.morris4x4center.com/cata...ust%20manifold

 

I should have mentioned it’s the 5.2 v8. Lots of choices for the 4.0

 

3" dia Stock front cat on a '99 XJ


Larger MagnaFlow California certified replacement Cat installed due to poor numbers on the last smog test; confirmation by infrared thermometer readings of the inlet and exit temps on the old Cats

After the new cats were installed we went on a trip. Unfortunately, about 30miles up the highway from home, I noticed smoke rising from below the jeep. I pulled over and observed a fire from ATF fluid spilling on the exhaust pipe. Fortunately, we were carrying a fire extinguisher. Once the flames were extinguished, we called a towing company and had them tow the Jeep to a local automotive shop. The mechanics observations:

“REMOVED THE TRANSMISSION AND FOUND RANGE SENSOR AND FRONT SPEED SENSOR MELTED. TRANSMISSION COOLER LINES DAMAGED AND THE FLUID BAKED. NOTED THE NEW CATALYTIC CONVERTERS AND INSPECTED. AFTER MARKET CATALYTIC CONVERTERS ARE CALIFORNIA LEGAL BUT NOT THE SAME OEM STYLE. THERE IS NOT MUCH ROOM IN BETWEEN THE CATALYTIC CONVERTER AND THE TRANSMISSION, SUSPECT HEAT FROM EXHAUST DAMAGED THE TRANSMISSION AND SENSORS. (CUSTOMER STATES THAT THE FLOOR BOARD GETS SO HOT THAT IT BURNT HIS DOGS FEET). REPLACED THE TRANSMISSION AND SENSORS. FLUSHED THE TRANSMISSION COOLER TWICE. TEST DROVE BREIFLY. VEHICLE RUNNING NORMAL AND SHIFTING PROPERLY. CHECKED FUEL TRIM TO SEE IF CONDITION MAY BE EFFECTING THE TEMPERATURE OF THE EXHAUST. FUEL TRIM IS NORMAL.”

Image of burnt sensors NOTE : heat is a major cause of automotive transmission failures

Prior to driving the Jeep home, I installed a Heatshield Products insulating mat over the top of the front cat. With additional shielding, the catalytic converter functioned well. After slow stop and go city driving, I observed a 360 degree reading from an infrared thermometer pointed at the top of the outlet side of the front cat below the shield and added insulating mat. The surface of the insulating mat and MagnaFlow’s shield read 180 degrees. The automatic transmission’s pan read 195, standard operating temp. This leads to the conclusion that MagnaFlow’s provided shielding is inadequate.Unfortunately, as stated above, MagnaFlow’s larger cat places heat very close to the transmission.

Heat Shield installed

In an effort to bring this to MagnaFlow's attention, I contacted Customer Service at MagnaFlow and discovered they do not return calls. In turn, I filed a formal complaint with the state Board of Automotive repair (BAR). Though they do not have authority over Manufactures, they did get a response from MagnaFlow's engineering department who reviewed the information. This was their response:
“… We have reviewed your liability claim and are denying the same. While our universal replacement part may be dissimilar to the OE part, there is nothing about the part and its proper operation that could have resulted in damage to your transmission. We note that the part itself was not damaged and is still in use. Our warranty is limited to replacement of the Magnaflow part, if determined to be defective.

Best regards

Peter Nitoglia “
My mechanic certainly doesn't agree with this self-serving assessment . Personally, I WOULD NOT recommend this company

 

So I've been waiting for my exhaust to rust off so i can justify in my head replacing it lol. Well the day has finally arrived. The tail pipe rusted through just on the outlet side of the muffler so just rocking the cat and muffler for a short time.

I've looked up a lot of videos and used the thread of sound comparisons but I'm still having a difficult time deciding.

​​​​​I have a decent drone at highway speeds and it lets you know it's there when you step on the skinny pedal. I listen to music fairly loud but it's not drowning out tunes though its noticeable. Trying to see how this "setup" compares to aftermarket systems if anyone has been in a similar scenario. I.e. is a certain system louder/softer than this in their experience.

Thanks.