Replaceing Cats

i,ve used one on our old 91 tbi van,. it worked fine to pass emissions

Do they need adapters or are they made wide enough to just slip over the pipes after you cut the old convertor off?

Is this a true universal or the aftermarket pre shaped ones? I did a universal on my wagon a few weeks ago, straight forward sawzall the old one out, slide the new one in clamp and go.

It depends on the tubing size. Make sure it will either fit over or in the original tube. I think fitting over would be better if you ever have to replace them again. You can sell the old converters for $50-100 EACH, so don't throw them away.

Fred Kiehl wrote:

It depends on the tubing size. Make sure it will either fit over or in the original tube. I think fitting over would be better if you ever have to replace them again. You can sell the old converters for $50-100 EACH, so don't throw them away.

Just dont sell them for reuse by someone thinking that these will help his clunker pass the sniffer test.Would work good for a visual check!

I did not mean to imply that a person could use them, that is the scrap price.

Where can I get that kind of money for my old cats? I put new ones on my car when I installed my new exhaust a few months ago.

Bull wrote:

Where can I get that kind of money for my old cats?  I put new ones on my car when I installed my new exhaust a few months ago.

Call your local scrap yards and see what they pay, OEM cats are worth decent cash, aftermarket not so much but still worth scrapping.

Speaking of cats, is there any way to tell if the cat is starting to go? The passenger foot well in my Roady wagon is getting a little warm, so my wife says. The car still drives fine, and I thought the major clue the cat was bad was poor performance. Gas mileage is still the same as well. Is there a temperature that they operate at? The guy at the shop I use has a hand held temp gauge that you point at something, and it give the temp of the object. But he is unsure of the normal running temp of a hot cat converter. Any thoughts anyone?

does your exhaust smell like rotten eggs? if so its probably bad

if the entire length of the cat including the inlets and outlets are a consistent temperature then its fine but if the inlet area is a lot hotter then the outlet you know its probably clogged up.

When cats go, they usually are clogged, and your performance starts to go away. The only reason you get rotten egg smell is if you are running rich, and the cats are still working. A rich mixture will tend to clog the cats in short order. The cats sometimes get hot enough to ignite dry grass under the car. The floor of the car will get warm with just the exhaust pipe under it, so I would not be surprised to have a warm floor with a cat. Unless you start to loose performance, or it does not pass emissions, I would not worry about the cats. I only ever had one cat go bad, and it was from running rich, and the symptom was loss of what little performance my LO3 had.

Mark 96 Roady wrote:

Speaking of cats, is there any way to tell if the cat is starting to go? The passenger foot well in my Roady wagon is getting a little warm, so my wife says.

where i live,. its time to lift the carpet and see whats going on,. hot carpet usually means the car has shed its floor above the cat,. there is a piece of tin there that shields the floor from the heat,. it may have fallen off,.

phantom 309 wrote:

Mark 96 Roady wrote:

Speaking of cats, is there any way to tell if the cat is starting to go? The passenger foot well in my Roady wagon is getting a little warm, so my wife says.

where i live,. its time to lift the carpet and see whats going on,. hot carpet usually means the car has shed its floor above the cat,. there is a piece of tin there that shields the floor from the heat,. it may have fallen off,.

Good idea, I forgot about the heat shield. The car is from the south, so I'm sure rust isn't an issue, but the heat shield sure could be.

I can tell you that my car has all the factory shields, and when towing a trailer this summer, it got hot inside. It had two issues. The door was leaking water and the hvac was leaking water into passenger side cab. No issues with the cat, but with the water leaking in and below the carpet on the passenger side, when the cats got hot with the towing, it became a sauna inside the car. That water got hot and the humid hot air made the inside pretty warm.

On another note, I installed aftermarket cats on the car (walker). Everything is working fine, but I think I have narrowed my exhaust tick to them. I don't know if they use a thiner, single wall design, but I hear the tick in that area. No exhaust leaks I can find, so I have to assume its them.