Cat questions.
Thread Starter
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
Cat questions.
I hope I can get the correct answer here as always.
First, how much HP gain is there with hi-flow cats vs OEM cats.
Second, I have a cat going bad (smell of routen eggs)..will it harm the engine driving with a bad cat until I have it/them replaced?
Thanks for an answer...
SLPRC5
First, how much HP gain is there with hi-flow cats vs OEM cats.
Second, I have a cat going bad (smell of routen eggs)..will it harm the engine driving with a bad cat until I have it/them replaced?
Thanks for an answer...
SLPRC5
Melting Slicks
Joined: Sep 2006
Posts: 2,041
Likes: 4
From: Rockford Illinois
I hope I can get the correct answer here as always.
First, how much HP gain is there with hi-flow cats vs OEM cats.
Second, I have a cat going bad (smell of routen eggs)..will it harm the engine driving with a bad cat until I have it/them replaced?
Thanks for an answer...
SLPRC5
First, how much HP gain is there with hi-flow cats vs OEM cats.
Second, I have a cat going bad (smell of routen eggs)..will it harm the engine driving with a bad cat until I have it/them replaced?
Thanks for an answer...
SLPRC5
Thread Starter
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
Melting Slicks
Joined: Sep 2006
Posts: 2,041
Likes: 4
From: Rockford Illinois
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Thread Starter
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
One friend told me that since my car was tuned too rich for a couple of thousand miles and now that it is tuned properly and leaner, that it could be burning off the build up in the cats causing the egg smell and after some driving the smell will go away.
Hopefully he is correct.
Le Mans Master
Joined: Feb 2006
Posts: 5,267
Likes: 40
From: Phoenix AZ
The O2 sensors that control your air fuel mixture are before the cats. The O2s after the cats are there only to know if the cats are still working or not.
If your cats are giving you the rotten egg odor, your cat(s) are running too hot. This can be either from too rich, or too lean (as in an air leak or air injection leak.)
If it continues , it will melt down and clog up. Then you have a restriction and it will eventually feel like you are pulling a trailer.
Mazda RX-7s had 3 cats inline. They would clog up and you could punch it in neutral and it would only rev to 4k
Thats how you know they are really wasted
If your cats are giving you the rotten egg odor, your cat(s) are running too hot. This can be either from too rich, or too lean (as in an air leak or air injection leak.)
If it continues , it will melt down and clog up. Then you have a restriction and it will eventually feel like you are pulling a trailer.
Mazda RX-7s had 3 cats inline. They would clog up and you could punch it in neutral and it would only rev to 4k
Thats how you know they are really wasted
Thread Starter
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
The O2 sensors that control your air fuel mixture are before the cats. The O2s after the cats are there only to know if the cats are still working or not.
If your cats are giving you the rotten egg odor, your cat(s) are running too hot. This can be either from too rich, or too lean (as in an air leak or air injection leak.)
If it continues , it will melt down and clog up. Then you have a restriction and it will eventually feel like you are pulling a trailer.
Mazda RX-7s had 3 cats inline. They would clog up and you could punch it in neutral and it would only rev to 4k
Thats how you know they are really wasted
If your cats are giving you the rotten egg odor, your cat(s) are running too hot. This can be either from too rich, or too lean (as in an air leak or air injection leak.)
If it continues , it will melt down and clog up. Then you have a restriction and it will eventually feel like you are pulling a trailer.
Mazda RX-7s had 3 cats inline. They would clog up and you could punch it in neutral and it would only rev to 4k
Thats how you know they are really wasted
tune is lean 12.8 the egg smell started. I was told it could be because now that the tune is leaner it is burning off the residue left by the rich tune. So drive it around for awhile to see if it clears up. Today there was less of a smell.
Melting Slicks
Joined: May 2006
Posts: 2,303
Likes: 40
From: Edmonton Alberta
I'd bite the bullet and change the stock cats for after market, heck you already have long tubes.
I don't think you will do any damage in the meantime. Cat's have to run somewhat hot - that's the way they create oxidation.
I don't think you will do any damage in the meantime. Cat's have to run somewhat hot - that's the way they create oxidation.
Melting Slicks
Joined: Nov 2005
Posts: 2,071
Likes: 0
From: clackamas oregon
I had a chev dlr check mine out because i can occasionally smell the rotten egg smell. was told it is due to additives in the gas. mine seems to only do it when going down a huge hill and down shifting to slow for a long distance. and not very often. i was told if the codes did not come on, nothing was wrong with them. maybe yours is the same and you dont need to spend any money right yet!
Thread Starter
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
I had a chev dlr check mine out because i can occasionally smell the rotten egg smell. was told it is due to additives in the gas. mine seems to only do it when going down a huge hill and down shifting to slow for a long distance. and not very often. i was told if the codes did not come on, nothing was wrong with them. maybe yours is the same and you dont need to spend any money right yet!
Thread Starter
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
Last edited by SLPRC5; Apr 14, 2007 at 02:32 AM.
Thread Starter
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
Just as mvvette97 said, after a couple of hundred miles of driving the new tune cleaned out the residue from the rich tune and the egg smell has gone away...
Thanks Marc
Thanks Marc
Melting Slicks
Joined: May 2005
Posts: 3,394
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From: Leon Iowa
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