The replacement exhaust system heated the passenger floorboard hot enough to burn my dog riding in the foot well. I added a UTV EXH shield kit:

 

Looking to see if anyone here has the MBRP cat back exhaust P.N. MBRS5534409 on their Cherokee. If so how loud is it? I am thinking about purchasing and was just curious.

 

how long does a stock cat live typically?

is it best to use a high flow cat for a replacement? performance and cost effective?


ive also had a thought of grinding out the stock dent below the down pipe and patching it with sheet metal. has anyone done this?

 

That dent will not affect anything. Cat performance depends on environmental conditions that it has gone through. I've not heard of a mileage recommendation per se.

 

I saw one piece of data that said a cat should last the basic life of the vehicle unless there are problems. I expect that on the 4.0 in average mechanical condition a cat would last at least 150k miles. Issues that will shorten the life are high oil consumption, excessively rich or lean conditions and use of diesel oil such as Rotella. Diesel oils contain higher levels of zinc in the form of ZDDP. The zinc contaminates catalytic converters used for gas engine applications and will shorten their life.

On the white 1991 XJ my son replaced the converter at around 170k miles. It made a difference in apparent performance. We both used MagnaFlow Direct-Fit P/N 23229.

 

I just noticed something - you have the converter mounted upside down. The built in converter heat shield is suppose to face down to help prevent overheating and catching on fire anything you are parked on, such as dry grass. Other than that I don't expect it makes any difference.
I added heat shields similar to what you used on the converter and muffler on my red '91 as there is no factory heat shields on the underside floor pan as far as I know. Have not had a chance to drive it since.

 

With the Flow-master cat mounted this way (BTW, the after market cat has "TOP" stamped on one side, that's the side I mounted facing up) and the accessory heat shield in place, I drove the Jeep about 50 miles.Then I measured the temp with an infrared thermometer: the side of cat measured 184 degrees, the insulated shield measured 144 just above where I measured before - a 12.7% improvement. With one layer of 3/8" closed cell poly insulation below the mat, I measured 106 at the top of the floor mat. I added a couple of more layers of poly below the mat to improve this number, but haven't taken another long drive. Good luck with yours

 

Looking to buy a B pipe/downpipe other than Walker but can't find any.
I have a Banks header, MagnaFlow cat and super 44 so I want something better than stock. Links would be greatly appreciated!

 

I doubt you'll be able to find better than stock online. Your best bet is to go to an exhaust shop and have one made. At least for me it's usually close in price or cheaper. From the header to the tail pipe Mandrel bent including my muffler was $160

 

When I went to go get my 1988 Jeep Cherokee smog checked the guy said i was missing a tube that connected the intake and I think part of the exhaust. He said it was to give the engine warm air when it's super cold outside, but I've never heard of anything like that. Is that an actual thing or was he just trying to scam me or something? Also, I've looked up videos of other people's engines and it doesn't look like they have the pipe that comes off the exhaust like I do.

Also here's some pictures of the two parts he said should be connected the first two pictures is the pipe coming off the exhaust and the third picture is what he said I need to connect it to.






Any help is greatly appreciated!

 

There is a tube there that sucks air from around the exhaust manifold and directs it to the intake to warm up faster or something. Mine had it and I ripped it off and threw it away

 

It looks like you have a 1990 or earlier. Most all vehicles in the 70's and 80's of all types had a similar setup to pull warm air from the manifold and direct it to the air cleaner inlet when cold. The warm air allows fuel to vaporize and better mix with the air. There would be a thermostatically controlled damper on the warm air inlet to the air cleaner. This is typically called a TAC system. It was an emissions reduction and cold performance improvement feature before fuel injection systems.

 

Can anything be done to the walker B-pipe to improve it? Maybe a ceramic coating?

 

I've never purchased one myself, but front what I've heard they're not even mandrel bent so they're worse than the factory pipe. I'd call around to exhaust shops and see how their pricing is near you. The guy here does good fast work and it's all mandrel bent

 

i need some info on a good aftermarket header for my 2001 xj limited.? thx