Okay, before anyone says use the search tool, I did. I searched for a y pipe to replace my front cat and has a O2 sensor thread built in. I found one from Jeg's which is this: JEGS Performance Products 31010 JEGS Off-Road Y-Pipes for Trucks

Then on the forums I searched and found a Walker one: Walker Exhaust 45166 - Walker Exhaust Pipe Connectors - Application - SummitRacing.com

Now, onto the details. My truck is a '91 F150 with a 302. Last year I had new exhaust put in from the front cat back. I replaced the rear cat with a high flow magnaflow cat and had 2.5" piping put in all the way back. I'm wanting to remove my front cat and still have the o2 sensor thread, so I figured buy a y pipe. I found out they were expensive besides the Walker one. My question is: would the walker one that says it's for the I6 work for my 302? Or should I go ahead and buy the one from jeg's. Also, does anyone know if the Walker one has an o2 sensor thread in it?

I'm fine with buying the one from Jeg's if I have to. I'd just like to get everyone's opinions on what I should do.

 

There are Y pipes for 5.0 trucks from Walker, Magnaflow, and Catco on Summitracing, just search under cat converters. You will need a 5.0 specific Y pipe too.

 

That Walker 45166 is not going to fit your 5.0L equipped F150. You would need a Walker 15742. Unfortunately it also comes with a converter, which you say you already have. And yes this y-pipe has the fitting for the O2 sensor.

You could remove the existing front converter and replace it with a connecting pipe to your Magnaflow converter.

 

Just cut the cat off and have an exhaust shop weld up a new piece and weld an O2 bung in it. Then take the cat to the scrap yard and that will pay for the exhaust work.

Thats what I did. Sold all 4 cats and got my exhaust completely redone for exactly how much I got for the cats.

 

Wonder if one of them would fit my 351w

 

If you have a 1991 F150 you would need a Walker 15849

 

97 F-250 but most of the exhaust stuff is the same between the 2 from what I understand.

 

I would also just have the exhaust shop replace the front cat with with pipe. Isn't your front cat a dual in single out? Just have them make a Y for that.

 

F250 and F350 share a lot of the same exhaust components. Not so much as the F150. I bet your F250 uses a huge single converter like my '92 F350. If yours is a lighter duty version then it may have the two converter setup like the F150.

If you have the big single converter then your truck needs a Walker 15762. That is for a converter only, no y-pipe. It is also a 49 state version, not for use in Cali.

The y-pipe is sold separately from the converter. If you truck uses a single O2 sensor then a Walker 40572 or 40585 depending on transmission may fit. The parts books get a little fuzzy around the '96 time period for these trucks.

 

Dual in single out converter and muffler (for whatever reason they didn't just run 2 cats and a crossover pipe) Thought real hard about having a pair of flanges cut and just welding some straight pipes on them with a dual in dual out muffler.

 

Yea it is. Isn't the y pipe welded to the cat though? I don't want them to mess anything up. So, is this probably the best and cheapest route?

 

I just got some work done at my local exhaust shop. $170. They remove the stud that I broke off in the manifold and gave me a new exhaust from the manifolds back. the pipes go into a dual in/single out custom made muffler, similar to a mello-tone or flowmaster. They even welded in a bung a reinstalled my O2 sensor.

 

Thanks guys. In the spring I'll most likely go to my local exhaust shop and have them fab something up for me.

 

I live in Cal. and have tried to get a muffler shop to do modification work on exhaust. They are saying they won't dual out the pipes til it gets past the back cat. Big fine if caught.

 

Thats because most of the aftermarket cats are not CALI compliant. People do that here all the time and run a new cat on each pipe.