A previous owner (why are they all hack jobs?) had cut the 4 bolt flange from the very end of the stock Y pipe, and replaced the intermediate pipe and went with no cat. My goal is to replace the cat however I cant buy a slip on style since the end of the Y pipe is oval.

If I replace the Y pipe with a factory used take-out with the flange in tact, where do I source the flange that attaches the end of the cat to the intermediate pipe?

I am looking at Catco 4116 for the converter, just wondering about the flange that attaches the back of the cat to the intermediate pipe.

Does someone make an I pipe with that flange attached?

Thanks!

 

Junkyard + Sawzall?

Hell, I would send you mine as I plan on putting longtubes on next weekend, but Im guessing you dont want to wait that long?

Can I ask why you plan on putting the cat back on? There were no emissions laws when I was in school in Marquette.

 

The heavy exhaust fumes get to me. To the point where it discourages me from driving the car.

I am in no huge rush, just a matter of getting this right.

 

Well shop around, and if you dont find anything, Ill totally send you mine if you pay the shipping. I got my headers and x-member today, and exhaust is coming in next week, and hopefully Ill get it all in by next weekend, but, either way I expect I should at least have the originals out by that point.

 

Just to confirm, you have the 4 bolt flange cat setup correct?

 

Damn...

I had to look.....No its not. I'm glad you asked. I assumed they would be the same.

My mistake

 

No problem. I know that the 85 HO cars have a real unique exhaust setup.

Thanks for your willingness to help.

 

Brad, check out this website.http://www.apemissions.com/performan...et-2/overview/

I'm pretty sure I found a stock replacement '85, HO, 4 bolt flange Y-pipe here.

 

Here you go.
http://showmetheparts.com/apexhaust/

 

I have a bare flange or two.

 

Charlie, after plugging in my info on that last link, I am looking for the piece with the p/n 78117, however it is not in the list down below. I enter the number in the search bar and receive no matches. Thanks tho. Any other places you could think of, let me know.

jmd,

You said you have a flange. Is this for the rear cat to pipe connection? Is there a bit of pipe attached to weld to the existing 2.5 I pipe?

Thanks!

 

It's been a few years since I've looked at the oval Y-pipe, but I would expect a person could have an exhaust shop expand the pipe round and adapt it to a standard cat. Or just get a Y-pipe from a later TPI car. I can't think of any reason other than originality to stick with the oval pipe.

 

The exhaust shop swore up and down that it was modified to oval. Between that and the belt being removed from my AIR pump at the time, they wouldn't touch the car and refused me service. This had been the second shop that I had been to as well...

 

The oval pipe was definitely a stock feature... 84-85 on the L69 and LB9 are where I've seen them. I'd remove the y-pipe from the car, and just take the pipe to a shop with exhaust equipment. If they ask its for a "race car" "derby car" "agricultural well pump" etc, anything but a street car that has to abide by EPA standards. That gets the shop out of hot water liability. I wouldnt even mention trying to mate it to a cat...

The Magnaflow Y-pipe for TPI cars would be one way to cut the exhaust shop out of the loop. Add a direct replacement cat and intermediate pipe for an 86 LB9 and it should all bolt together.

I kind of wish I had a pile of 86-88 TPI Y-pipes laying around... They are about ideal for all the early cars and plenty of late cars. Probably the best all-around exhaust for most thirdgen drivers.

 

mtown where are you at? I see you say Michigan i may be able to find you a close shop to help. I have same issue out here basic shops wouldn't help. I had to call a performance shop. But in Michigan i have a few people i know that may be able to help.

 

Southeast Michigan