[Z06] Bad catalytic converter twice in 3 years?
01-31-2019, 08:22 AM
#21
Le Mans Master
I had this exact same problem a few years ago. Went through 3 cats. I think it ended up being a TSB fix. Our crappy 91 Octane doesn't help either.
02-01-2019, 05:16 AM
#22
Safety Car
I have used Boostane premium (not the professional) octane booster to raise our crappy 91 octane to 94 octane. The actual amount of additive/octane booster is only about 4.5 ounces per tankful. Do you feel this product may be an issue. Boostane states the premium blend is legal and safe for catalytic converters and 02 sensors.
02-01-2019, 09:56 AM
#23
Pro
I'd like to hear more about this "Chevy Customer Service"? You mean, there is somebody you can call and complain to, and they actually offer you money (" financial assistance" ) ?
Wow, I'd love a set of ears to tell about my fuel pumps failing a couple months ago. I have the same car as you, same mods (none) and less than 20,000 miles. Drive it to church once a week.
Good luck with the cats. I am sure they'll make it right.
Wow, I'd love a set of ears to tell about my fuel pumps failing a couple months ago. I have the same car as you, same mods (none) and less than 20,000 miles. Drive it to church once a week.
Good luck with the cats. I am sure they'll make it right.
02-02-2019, 12:09 AM
#24
Pro Mechanic
Pro Mechanic
I have used Boostane premium (not the professional) octane booster to raise our crappy 91 octane to 94 octane. The actual amount of additive/octane booster is only about 4.5 ounces per tankful. Do you feel this product may be an issue. Boostane states the premium blend is legal and safe for catalytic converters and 02 sensors.
The only active ingredient in pour-in octane boosters which is legal and actually works is methylcyclopentadienyl manganese tricarbonyl. Try and pronounce that after drinking a six-pack. "MMT" is a gasoline octane booster produced by the Afton Chemical Corporation, formerly known as the Ethyl Corporation. EPA allows MMT in U.S. gasoline at a level equivalent to 1/32 grams per gallon of manganese (gpg Mn), so, indeed, Boostane, and other products using MMT at .031 gpg Mn are legal.
Such products being "safe" for catalytic converters is debatable and depends on how long the cat is exposed to MMT and how long a period of time the maker of the product defines as "safe".
If "safe" means to the person marketing the booster that you can use the product at .031 gpg Mn for 25,000 miles, then yeah, it's safe. But what if "safe" to you means the same cat life you'd expect from gasoline with no MMT, ie: 50,000-75,000 miles? In that case, you loose, sucker.
Problem is most users have no way of measuring the gpg Mn of their gas and most users are going to put more than that in the gasoline, because the cheapskates that they are had them drinking the kool aid of MMT, ie: if some is good then, much more is better and I'm going to pour-in three cans of this s**t and save my *** a whole lot of money.
MMT in regular use, in proportions great enough to move a 91-oct premium unleaded to 94-oct, is going to eventually kill any cats on the engine. Plus, long-term use of MMT leaves hard metallic deposits on valve heads, piston tops, chamber walls and spark plugs. Here's another little tidbit. MMT octane boosters are much better at raising, an 87-oct gas to 91 than they are at raising a 91 to 94. Because of that, some octane booster makers market their products with "test" results gained with using the product in a regular unleaded gas, not using in a premium unleaded which is typical of how virtually all enthusiasts use those products.
One failed cat from use of MMT completely negates any savings from using MMT-spiked pump gas instead of 100-oct unleaded racing gasoline mixed with pump 91 in the correct proportion to get 94-oct.
A number of years ago I tested an MMT-booster marketed under the NOS brand in a mod'ed '95 ZR-1 I once owned. Yes, it was definitely effective in raising the octane a couple of octane numbers. Yes, it left deposits on the spark plugs, that orange-brown residue characteristic of MMT. No, my cats did not fail, well...at least not right away, however, about 18-months later, the car failed the California Smog Check. I diagnosed the failure due to bad cats. Two new stock cats and the car passed with flying colors. Just as a further test, I put the old cats back on and went to a smog station and asked for a "pre-test". The car went back to flunking.
I've never used an MMT booster again.
When I need 93 or 94 octane fuel, I mix Rockett Brand 100 unleaded with pump 91 at a ratio of between 1:2 and 1:3.
The following 2 users liked this post by Hib Halverson:
2k Cobra (02-02-2019),
Mike's LS3 (02-23-2019)
02-04-2019, 02:14 PM
#25
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St. Jude Donor '08
I have used Boostane premium (not the professional) octane booster to raise our crappy 91 octane to 94 octane. The actual amount of additive/octane booster is only about 4.5 ounces per tankful. Do you feel this product may be an issue. Boostane states the premium blend is legal and safe for catalytic converters and 02 sensors.
Ah, "Boostane". I think they are one of the best-marketed octane boost products available today.
The only active ingredient in pour-in octane boosters which is legal and actually works is methylcyclopentadienyl manganese tricarbonyl. Try and pronounce that after drinking a six-pack. "MMT" is a gasoline octane booster produced by the Afton Chemical Corporation, formerly known as the Ethyl Corporation. EPA allows MMT in U.S. gasoline at a level equivalent to 1/32 grams per gallon of manganese (gpg Mn), so, indeed, Boostane, and other products using MMT at .031 gpg Mn are legal.
Such products being "safe" for catalytic converters is debatable and depends on how long the cat is exposed to MMT and how long a period of time the maker of the product defines as "safe".
If "safe" means to the person marketing the booster that you can use the product at .031 gpg Mn for 25,000 miles, then yeah, it's safe. But what if "safe" to you means the same cat life you'd expect from gasoline with no MMT, ie: 50,000-75,000 miles? In that case, you loose, sucker.
Problem is most users have no way of measuring the gpg Mn of their gas and most users are going to put more than that in the gasoline, because the cheapskates that they are had them drinking the kool aid of MMT, ie: if some is good then, much more is better and I'm going to pour-in three cans of this s**t and save my *** a whole lot of money.
MMT in regular use, in proportions great enough to move a 91-oct premium unleaded to 94-oct, is going to eventually kill any cats on the engine. Plus, long-term use of MMT leaves hard metallic deposits on valve heads, piston tops, chamber walls and spark plugs. Here's another little tidbit. MMT octane boosters are much better at raising, an 87-oct gas to 91 than they are at raising a 91 to 94. Because of that, some octane booster makers market their products with "test" results gained with using the product in a regular unleaded gas, not using in a premium unleaded which is typical of how virtually all enthusiasts use those products.
One failed cat from use of MMT completely negates any savings from using MMT-spiked pump gas instead of 100-oct unleaded racing gasoline mixed with pump 91 in the correct proportion to get 94-oct.
A number of years ago I tested an MMT-booster marketed under the NOS brand in a mod'ed '95 ZR-1 I once owned. Yes, it was definitely effective in raising the octane a couple of octane numbers. Yes, it left deposits on the spark plugs, that orange-brown residue characteristic of MMT. No, my cats did not fail, well...at least not right away, however, about 18-months later, the car failed the California Smog Check. I diagnosed the failure due to bad cats. Two new stock cats and the car passed with flying colors. Just as a further test, I put the old cats back on and went to a smog station and asked for a "pre-test". The car went back to flunking.
I've never used an MMT booster again.
When I need 93 or 94 octane fuel, I mix Rockett Brand 100 unleaded with pump 91 at a ratio of between 1:2 and 1:3.
The only active ingredient in pour-in octane boosters which is legal and actually works is methylcyclopentadienyl manganese tricarbonyl. Try and pronounce that after drinking a six-pack. "MMT" is a gasoline octane booster produced by the Afton Chemical Corporation, formerly known as the Ethyl Corporation. EPA allows MMT in U.S. gasoline at a level equivalent to 1/32 grams per gallon of manganese (gpg Mn), so, indeed, Boostane, and other products using MMT at .031 gpg Mn are legal.
Such products being "safe" for catalytic converters is debatable and depends on how long the cat is exposed to MMT and how long a period of time the maker of the product defines as "safe".
If "safe" means to the person marketing the booster that you can use the product at .031 gpg Mn for 25,000 miles, then yeah, it's safe. But what if "safe" to you means the same cat life you'd expect from gasoline with no MMT, ie: 50,000-75,000 miles? In that case, you loose, sucker.
Problem is most users have no way of measuring the gpg Mn of their gas and most users are going to put more than that in the gasoline, because the cheapskates that they are had them drinking the kool aid of MMT, ie: if some is good then, much more is better and I'm going to pour-in three cans of this s**t and save my *** a whole lot of money.
MMT in regular use, in proportions great enough to move a 91-oct premium unleaded to 94-oct, is going to eventually kill any cats on the engine. Plus, long-term use of MMT leaves hard metallic deposits on valve heads, piston tops, chamber walls and spark plugs. Here's another little tidbit. MMT octane boosters are much better at raising, an 87-oct gas to 91 than they are at raising a 91 to 94. Because of that, some octane booster makers market their products with "test" results gained with using the product in a regular unleaded gas, not using in a premium unleaded which is typical of how virtually all enthusiasts use those products.
One failed cat from use of MMT completely negates any savings from using MMT-spiked pump gas instead of 100-oct unleaded racing gasoline mixed with pump 91 in the correct proportion to get 94-oct.
A number of years ago I tested an MMT-booster marketed under the NOS brand in a mod'ed '95 ZR-1 I once owned. Yes, it was definitely effective in raising the octane a couple of octane numbers. Yes, it left deposits on the spark plugs, that orange-brown residue characteristic of MMT. No, my cats did not fail, well...at least not right away, however, about 18-months later, the car failed the California Smog Check. I diagnosed the failure due to bad cats. Two new stock cats and the car passed with flying colors. Just as a further test, I put the old cats back on and went to a smog station and asked for a "pre-test". The car went back to flunking.
I've never used an MMT booster again.
When I need 93 or 94 octane fuel, I mix Rockett Brand 100 unleaded with pump 91 at a ratio of between 1:2 and 1:3.
The following users liked this post:
Mike's LS3 (02-23-2019)
02-13-2019, 12:52 PM
#26
Instructor
Thread Starter
Update: The dealer has my car again, and they verified that the cat is in fact in need of replacement. I gave the GM agent I'm in contact with the dealer information. She again reminded me there was no guarantee of financial assistance because my car is out of warranty. I stated that I am aware that my car is out of warranty, but the part that is being replaced is only 3 years old. The factory warranty is longer than that. She said that they only warranty replacement parts for 1 year or 12,000 miles, but that she would contact the dealer to see what she could do.
I don't have a good feeling about this.
I don't have a good feeling about this.
02-22-2019, 09:33 AM
#27
Instructor
Thread Starter
So GM told me they won't cover any of the expense of replacing the cat. They only warranty parts for 1 year or 24000 miles. This really sucks. EPA and CARB says a cat should last 7 years and 70,000 miles, and original factory warranty is longer than I had that cat installed. This will be the last GM product I ever own.
02-22-2019, 09:37 AM
#28
Its a 2007...why is it their problem?
Also, start looking at WHY this may be happening. Premature death of converters either you are burning too much fuel (o2 sensor wonky) or you are burning too much oil (valve guide clearances).
Also, start looking at WHY this may be happening. Premature death of converters either you are burning too much fuel (o2 sensor wonky) or you are burning too much oil (valve guide clearances).
Last edited by Apocolipse; 02-22-2019 at 09:39 AM.
02-22-2019, 09:46 AM
#29
Melting Slicks
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So GM told me they won't cover any of the expense of replacing the cat. They only warranty parts for 1 year or 24000 miles. This really sucks. EPA and CARB says a cat should last 7 years and 70,000 miles, and original factory warranty is longer than I had that cat installed. This will be the last GM product I ever own.
They can be very aggressive resolving consumer's auto repair disputes.
But I agree, something is causing them to croak early...
02-27-2020, 06:38 AM
#31
Melting Slicks
I use boostane on my c7z every tank about 4 ounces and at the track. I burned up the drivers side cat in 2018 after about 5 track days and the other one just recently after about 13 track days. It definitely works and turns things a little orange. It’s also extremely cheap. 10/gal for 100 and I’d need $40 a tank to raise my gas to 93 vs maybe $2 worth of boostane? I changed out the spark plugs and they had some deposits but nothing crazy. Neither cat failed due to boostane clogging it they just got too hot on the track. Sorry about your Vette but it’s over a decade old going to burn up some cats here and there.