Originally Posted by 7jeep

looking to redo my exhaust from the headers back. I'm keeping all the sensor an the like but want a better perfoming eaxhaust mpg an such. also not looking to make it loud just perform better without costing tons of money. will be doing throttle body mods and injector mods later on. the motor is stock no mods planned for it. i have a 2000 4.0 w/5 speed tran ax15. any help, and thank you.

Originally Posted by dylanXJ99

haha ooopppps. my fault. wasnt aware that you couldnt talk about frowned upon modifications. haha but preciate the reply. im just a young and dumb kid. soo ill just keep rocking the guttless system. sounds good and got a nice increase in power

Originally Posted by dylanXJ99

ok so i have a flowmaster 40, real nice sounding, i have some friends who have comepletely did away with there cats. just straight pipe into the muffler and it sounds great. so i wanted to do this mod, but not have to search for a shop to inspect my jeep and look over the removed cat. so i chose to just cut the cat off, and gut it. gutted it, welded it back in, sounds amazing for a 6cyl. the I6 sounds way better then most V6's. but my question is, i was told with gutting my cat, id get more back pressure, which could eventually burn up my valves. how true is this

Originally Posted by bothellbikes

I would di the opposite and cut off the muffler and leave the cat... Thats what i have with 2.5" out the back it sounds great

Originally Posted by Slick761

Not frowned upon, blatently illegal. Just one of the forums pet peeves

Originally Posted by 1plunk

From the cat back I recommend 2.5" pipe, and mudfrog (a vendor here) sells 2.5" tailpipe and muffler combos for around $170 shipped last time I checked, his site is performance curve (google) and I have no personal experience with headers but when I did my research, I was told to stay away from pacesetter

Best of luck to ya!

Originally Posted by 7jeep

Thank you.

Originally Posted by Disoriented Hillbilly

Ahem..... ^^^^

Originally Posted by Chex_Mex

Didn't feel like reading through the 101 pages of questions, so this may have been asked already before, but, how hot is too hot for the exhaust? I'm running round between 400-500F at the header / block interface, the runnin in the low 400's down the headers, 400-500F at the expansion bulb when it runs across the tranny, high 200's on the cat (as i just replaced it because it was hittin the low 400's), muffler is around mid 300's, and the tail pipe is on the higher end of the 300 range.

one thing i noticed, all the rusted pipe was where the higher tempereatures were, do i just need to replace everything, or is 500F normal? (it's not glowing yet, lol)

Originally Posted by mudfrog

Aside from the manifold / header the cat will typically be higher than the rest of the exhaust. It's odd that yours is running in the 200's then your exhaust gets hotter afterwards.

If I remember I'll grab my temp gun and take some readings tomorrow.

Originally Posted by 92xjozee

Im looking to get a Flow master 40 series muffler with a new tail pipe as well, any cheap recommended bundles that come with both of those?

Originally Posted by Slim357

Ok so how can I make my jeep like on the verge of being so loud it gets you a huge fine? I currently have a glasspack and no cat. but its not near loud enough. Saw a Cherokee the other day that was so loud i could barely hear my radio over it and I have it turned all the way up. BTW I do have to have some sort of muffler due to inspections here.