Problem: Crumbling old catalytic converter.

 

Best Cheap Solution: ????????????

Do you wanna keep it? Do you live in an E-check state?

Do you wanna keep it? Do you live in an E-check state?

1. Yes.

2. No.

Junkyard or if you dont have to have it, have someone make up a pipe to replace it.

A used section in GC, would be the best/lowest cost solution. However, if you want the cat to function as it was designed, a universal aftermarket cat is what you want. Cats have a limited lifespan, and the chances of finding a good used one is not very good. Alternately, the price of an OEM pipe would be pretty steep.

 

Fortunately, that section of the pipe has a long, straight run, so splicing in a cat shouldn't be too bad. You could probably fab something yourself , if you can't find a pipe-bender who's willing (muffer shops can be kinda picky about doing what you ask them to do). Also, by fabbing your own exhast system, you are not stuck with the OEM muffler, and the location it mounts to the undercarriage.

good luck, John

Thank you gentlemen. I can't go used because it's illegal here to mount a used one, and I don't have the torches/cutting tools/bending gear etc. to do my own exhaust work.

 

Looks like universal aftermarket is about as cheap as I can hope for.

Thank you for the input.

Bill

Thank you gentlemen. I can't go used because it's illegal here to mount a used one, and I don't have the torches/cutting tools/bending gear etc. to do my own exhaust work.

 

Looks like universal aftermarket is about as cheap as I can hope for.

Thank you for the input.

Bill

If you would go to the junkyard and pull the whole y pipe they would not know it was used.Besides it would be replaced with an OEM one from another sube.

If you would go to the junkyard and pull the whole y pipe they would not know it was used.Besides it would be replaced with an OEM one from another sube.

 

I can't speak for everywhere, but all the junkyards I've ever been to, they cut the cats out of the Y-pipe before putting the car in the yard.

 

 

if it's the cat in the Y, if you can't find a junkyard one, don't even think about replacing the whole thing. your options there are OEM from a dealer (think many hundreds of dollars, at least), or custom.

 

use a long screwdriver, or piece of rebar to knock up the remains of the cat and let them fall out of the cat. then, if you really want to have that cat in there, cut a piece of the pipe out further back, and clamp in an aftermarket one (which still won't be cheap at all).

 

besides, assuming by your screen name that this is a 90 loyale, you've already got 2 in there.....

Ebay sometimes has cheap brand new ones. Then get someone to weld it in.. Expencive for an old roo, but if you want legal you gotta pay.

Thanks again gents. Had the rear (small) cat (or resonator or whatever that thing was) cut off by my exhaust man about two months ago after the pipe broke on the connection there. We're a non-emissions check state. So it's straight piped from the main cat aft to the muffler now. The guts in my main cat rattle around and are an annoyance, but I can't legally straight pipe the whole thing. The aftermarket cat options are confusing for the ignorant, such as myself. The cheap $59 deals appear to be the "rear" (small) cat that I don't want. Can I just find the cheapest "front" cat and have the exhaust boys mount it, like they would a new muffler - or am I looking at a more complicated cat+Y Pipe arrangement?

I can't speak for everywhere, but all the junkyards I've ever been to, they cut the cats out of the Y-pipe before putting the car in the yard.

 

 

if it's the cat in the Y, if you can't find a junkyard one, don't even think about replacing the whole thing. your options there are OEM from a dealer (think many hundreds of dollars, at least), or custom.

 

use a long screwdriver, or piece of rebar to knock up the remains of the cat and let them fall out of the cat. then, if you really want to have that cat in there, cut a piece of the pipe out further back, and clamp in an aftermarket one (which still won't be cheap at all).

 

besides, assuming by your screen name that this is a 90 loyale, you've already got 2 in there.....

Most of the times the you pullits dont touch anything but the gas tank. The problem though is you got to get it before the junkyard vultures get to them. Around here we have upulls and a group of lets say not so legal people stand out side all day and wait for a car to come in. AS soon as they put it on the ground they swoop in and strip it then take the parts to a garage or whatever then re sell them. They usaly dont touch old subes, they just want the ricer cars.

If you would go to the junkyard and pull the whole y pipe they would not know it was used.Besides it would be replaced with an OEM one from another sube.

 

 

It is against federal law for Junkyards to sell used cats.

It is against federal law for Junkyards to sell used cats.

Most you pullits dont care. Besides most of the guys where you pay dont know that the cat on a sube is part of the y pipe. I got lucky when I lived in AZ and found a good y pipe that the cat was already hollowed out. Federal law also says you must enter the country legally but they dont do a very good job inforcing it.:-\

I've only seen it happen once (someone getting turned away at the JY) for "emissions" equipment. And it was at one of those uppity U-Pull places that are corporate owned.

If you make yourself known at the good-ole-boy yards, your $$ is always good. But again, the problem is finding a used cat that's worth the bother. As mentioned above, there's a market for scrap cats, and that would limit their availabilty even further.

good luck, John

Has anyone cut open a y-pipe cat? Do the pipes merge together inside the cat and then go through a catalyst? Or is it both pipes open up into a separate chamber to the catalyst?

Has anyone cut open a y-pipe cat? Do the pipes merge together inside the cat and then go through a catalyst? Or is it both pipes open up into a separate chamber to the catalyst?

I cut the pipe directly behind the y-section. The cat is inside the y, after the pipes merge. I then took a wood hole-saw bit and drill bit extension to reach into the y, and hollowed out the cat. Then started the motor with the pipe still cut, not joined back together, to blow out the cat material. Then used a connector piece about 6" long and two u-bolt pipe clamps to join it together.

 

Reason I did this is because my mileage had dropped to 20; used to be 28 or so. At 170K miles the cat was getting pretty plugged up. Now my mileage is about 30 (haven't run thru a full tank of gas yet to be sure, but 30 is about right).

 

Edit: The 6" connecting pipe is 1.75" internal diameter, with clamps to match. You can use a battery-powered drill; the cat doesn't give any resistance that would require a high-torque drill.

That's interesting....

Maybe I've gotten my terminology crossed up, but I always thought that the catalytic converter was located in the second pipe. What Tom describes (within the Y pipe) I considered to be the resonator.

Am I getting it backwards, or are there actually two CATs?

???

John

That's interesting....

 

Maybe I've gotten my terminology crossed up, but I always thought that the catalytic converter was located in the second pipe. What Tom describes (within the Y pipe) I considered to be the resonator.

 

Am I getting it backwards, or are there actually two CATs?

 

???

John

 

The y-pipe definitely holds a catalytic converter. I myself thought the second pipe was a resonator, but it turns out that that is a cat too!

The y-pipe definitely holds a catalytic converter. I myself thought the second pipe was a resonator, but it turns out that that is a cat too!

 

Thanks for clarifying that.

I always assumed the "second" CAT is where the air flow restrictions became problematic. Definitley enough ceramic material in there, that's for sure!! I'll have to try your method for clearing out "CAT #1".

John

 

 

Thanks for clarifying that.

I always assumed the "second" CAT is where the air flow restrictions became problematic. Definitley enough ceramic material in there, that's for sure!! I'll have to try your method for clearing out "CAT #1".

John

 

The part I didn't mention is that my rear cat is almost new, so I knew that wasn't the problem.

I may not end up resolving this with a nice clean cheap solution, but it sure feels good to know that other good soobers are as ignorant as I am about the catalytic converter setup on our fine cheap beasts. Thanks for posting. I'll just keep rattling around town for now like a guy who can't afford a $500 muffler job. Which is what I am.

Is the O2 sensor mounted before the cat in the y pipe or does it matter if you gut it?

The o2 is before the car. And gutting it would only cause a CEL on obd2 cars. It will just pollute half as much as a old small block from the pre-cat era without it...