What is the best exhaust to run on a mid 90's 6.5TD, im thinking 3'' all the way to 3 1/2 tip? The cat will be gone..What is a good muffler? or should i run just a straight pipe, straight back?3 1/2''??thanks in advance.

-Eric

I asked a while ago if 3", 3.5" or 4" which is better. From what I seen it's all up to the user (you). I'm runnong a 3" down pipe to 4" no cat with a straight thru muffler. I didn't notice much difference with or with out the muffler. In this case as long as you get rid of the OEM down pipe you doing good the rest IMO is up to you.
BTW Welcome, and go by the FAQ and by the sticky update your signature line(far left on main tool bar in Users CP button) to include your truck's info, and any mods you have on it, keeps us from incorrectly diagnosing a problem.

I spent several months researching mufflers and exhausts for my truck, basically looking for a good improvement in mileage but I was not going to accept increased noise as I firmly believe you don't have to increase noise. I've learned a lot. You'll be very lucky to find a significant improvement in mileage, but you will gain some horsepower on a dyno and feel the improvement in daily driving. My OEM muffler had a big hole in it, so I was shopping. You can read about the dyno results and if you think you'll be pulling hard, then a larger pipe may benefit you.

I set up a little experiment to learn all of this, it cost me a bit, but was lower cost than buying a full aftermarket system then learning what I did. I bought a 4 bolt flange welded to a 3.5" pipe (From Pinnacle) which bolted to the turbo down pipe where I connected 3.5" pipe all the way to the back, including a Flowmaster tail pipe and a Donaldson muiffler. This replaced the converter trap (temporarily) as well.

The best economy I've got with my truck was still with the factory system (21 mpg), the aftermarket muffler I used was noisier than I will accept (best choice I think would be a Duramax muffler - if you can find one), and then getting something that fits like the factory system is a challenge. I ended up going with a new factory muffler/tailpipe to replace the whole works and I'm very satisfied. It cost less than what some of the aftermarket kits are charging now as well ($285 to the door).

I rarely see more than 2200 rpm, and really couldn't find the benefit I was seeking for my driving style. If I would see a consistent 2 mpg improvement from the exhaust itself, I might have reconsidered. My exhaust temps didn't change either. I saw an EGT drop when I put on the 1997 air intake and switching to DSG timing gears, but cruising temps with the larger pipes were the same, about 500-550F at 65 mph.

Where did you get your stock replacement parts from?

Hey 95YUKON Please update your signature area too for future reference. That helps others see what your running when talking bout your rig.
Thanks

Budroe,
I usually get all my genuine OEM GM parts from www.teamchev.com, Gale is the partsman who I talk to. They've always been the all time low cost source for most of the parts GM sells. I have yet to find any place that beats their delivered price.

The muffler/tailpipe I bought for my truck was one of 9 left in the nation, and from what I learned, GM will not be making any more. Not surprising as the Yukon is a rare diesel in the first place and they usually don't wear out until you get near 200k miles.