So after losing my tailpipe, I've been searching for a new exhaust. I need to keep my cat in ny, so I want a catback system. I cant find any catback systems at all, all of them are turbo back. Does anybody make a catback system?

 

I can't say I have ever seen one for the Cat equipped older trucks. You could always get a turbo back and a reducer ( think outlet of cat is 3-1/2" ) and go that way ( cut the down pipe at the right location ), or just get a stock replacement muffler and tailpipe.

Another way to run the bigger 4" turbo back would be to find a 3rd gen owner that pulled his kitty, they were 4" and you could put it in the correct location for your 97, the inspector would never know unless he had 2 of them side by side........

Besides, what is this tailpipe thingy that you speak of?

 

Thanks for the reply. I never thought about using a turbo back and a reducer, a good idea. I think its either that or a stock replacement like you suggested. Thanks again for the help.

Tailpipe? We dont need no stinkin tailpipe.

 

So I'm going with the turbo back system spliced in after the cat idea. I know the turbo back system has 4 " pipe, is the size of the stock pipe 3"? I plan on leaving a short piece of stock pipe in the cat, than getting a 4" to 3" reducer and attaching the new system. I just wanted to make sure the stock pipe was actually 3"

Thanks again for the idea

 

How picky are the inspectors out your way? I thought since your truck is over 15 years old you'd be good to go without a cat but who knows these days...

I did find that magnaflow makes a diesel 4" slip-on cat, not very cheap (can get a whole turbo back for the same price). Sure would hate to see your 4" downpipe go to waste though!

4" Cat

 

I don't know if there would be any benefit from a larger than stock exhaust pipe if you leave the cat in.

 

Unfortunately in my area all diesels are ran on emissions regardless of weight or year, so I have to keep the cat. I wasn't really going for a performance boost, just figured if I was buying a new muffler and tailpipe I'd rather not go stock. A stock set up cost about as much as a new turbo back. I'm just trying to make sure the stock pipe is 3" and with the new pipe being 4" a 4 to 3 reducer will work.

Thanks for the replies

 

'choppers,

What kind of emissions test do they do? Do they actually look for the cat? If it's an opacity test, you certainly should pass without the cat. I do and have a reading less than 2% with a limit of 20% and I'm running those smokey 370 marine injectors (In CT, they put the truck on the rollers and test opacity at 25mph). I haven't looked in a number of years at my ol cat that's in the garage but I thought the pipe was larger on the cat allowing a 4" to be welded to it. A pair of calipers would tell you if you could go that route. Last option if you want the cat for show only is to knock out the inners and weld it in place. Of course the law man would say:

 

Any diesels 97 and newer and over 8500 gvwr get a full diesel emissions and safety test.



Here's nys website


http://www.dmv.ny.gov/vehsafe.htm#diesel

Good ol' New York!

 

Just looked at the stock exhaust catalog, that might work out better than I intended. According to the parts manual for replacement exhaust, the pipe from the engine to the cat is 3" and cat out is 4", so you should be able to just cut it off and put it on.

You might want to verify my info, I couldn't get the Walker exhaust catalog to load so I had to use the AP catalog. Napa for sure could tell you what size it is, and you will have to be buying a heavy duty clamp anyway........

 

That would be great if I could just slip into the back of the cat. I'll crawl underneath and check before I order a system.

Thanks again for all your help

 

If most folks looked at how small the "exhaust hole" in the turbo is, you would never entertain the idea of spending more on a larger exhaust system. I'm pretty sure the bigger exhaust won't hurt anything (except the wallet) but it's doubtful much is gained........................the gain pro isn't zero bet it's close though.

 

Stock exhaust will cost me $260, and a turbo back is $280. I'm really just getting a better sounding truck, I agree it does minimal if any performance increase.

 

Thanks again PatDaly, I installed a 4" diamond eye exhaust right behind the cat. The pipe exiting the cat was already 4" like you thought, slipped the new muffler on and installed both tailpipe sections. Doesn't sound too much louder or different than the stock exhaust, but I didn't really want loud anyway. Worked out good.

Thanks

 

Actually there is a gain in lowering high exhaust gas temps which can be beneficial if you are towing heavy....I agree that performance wise the gains are minimal.