cat. converter
- Thread starter jlat
- Start date
Today's catalytic converters are infinitely better than the original style with pellets so you can run one without it negatively impacting performance. In fact, buying "high flow" cats as an upgrade can be pointless in many cases, as OEM cats are all high flow these days and last much longer than before. You could go to a salvage yard and pull a factory unit from a police cruiser or "SS" anything and it will presumably outflow ones of the same size on other V8 cars, but that really just comes down to which type of converter it is. I'm reusing the stock ones on an all new system for my '04 Regency Sierra but wouldn't hesitate to buy any number of the universal Honeycomb style that run $100 or less each- I even considered adding them to my Cutlass, which is absolutely unheard of for me. The OEM converters are designed to last a minimum of 80k miles and some are designed to survive twice as many, though driving style and vehicle maintenance both play vital roles. Aftermarket catalytic converters are often only intended to last 25k miles but can be useful much longer in the right conditions.
Having the converter will make a slightly noticable difference in decibels as well as knock off a small amount of rasp, and I know there are honeycomb versions that look very much like our originals. Using such a piece would help avoid the drone you mention, smells, and a closer look during inspection with very, very little to no downside. I say that as a life long fan of headers and excessively large straight pipe so it's not something I'm just making up, I've been convinced by people smarter than me. These people have performed ABA testing, measured flow and performance with equipment I couldn't afford to look at, and have seen every fresh idea in the last 50 years. I always hated Quadrajets, catalytic converters, and EGR valves but now I'm living proof that you can teach an old dog new tricks. Well, proof that if you explain it to me enough times I may finally understand.
In this application I could go either way and would happily try both but I like messing with exhaust systems for some reason.
Having the converter will make a slightly noticable difference in decibels as well as knock off a small amount of rasp, and I know there are honeycomb versions that look very much like our originals. Using such a piece would help avoid the drone you mention, smells, and a closer look during inspection with very, very little to no downside. I say that as a life long fan of headers and excessively large straight pipe so it's not something I'm just making up, I've been convinced by people smarter than me. These people have performed ABA testing, measured flow and performance with equipment I couldn't afford to look at, and have seen every fresh idea in the last 50 years. I always hated Quadrajets, catalytic converters, and EGR valves but now I'm living proof that you can teach an old dog new tricks. Well, proof that if you explain it to me enough times I may finally understand.
In this application I could go either way and would happily try both but I like messing with exhaust systems for some reason.
Sweet_Johnny has a point about the cost of converters. To get a GOOD one, you'll spend more money than one that would get you by for a few years. Not all converters are made the same. But yeah, basic converters can be had for less than 100 bucks in most cases.
Depending on how often you drive the car, spend accordingly on a new converter if it needs it. Converters weren't designed to last forever. There's a finite amount of conversion materials in one, so you have to spend accordingly.
Likely you had/have a dual bed converter on the Regal. You can tell as it has an A.I.R. inlet port from the A.I.R. system on it that goes right between the beds. So that's going to cost more. The issue with most engines in the 80s is that they were designed and developed in the 60s or 70s before emissions was a consideration. So converters had a lot to clean up. Later, engines were designed to burn cleaner and more efficiency (and a benefit to that came extra HP) so catalytic converters did not have to be of the same design, as well as engineering advancements on those as well. But 40 years is asking a lot from a cat converter. Mainly more for mileage than age, obviously, but I've seen rust get to stock converters as well.
I think this one is stock replacement for turbo regal from Magnaflow and is a dual-bed. #93439. I've never used any aftermarket ones, but have never heard anything bad about them. $312 for the Federal compliance one, but you'll probably never replace it again in your lifetime I would imagine. But it does have a 5 year warranty, whatever that entails.
For those with Olds V8 engines, Magnaflow makes a direct-fit Fed Compliant dual-bed for $157 (2 year warranty). #23427
The CARB compliant California universal job is nearly $700. (5 year warranty) California is always the pimple on America's azz and has to be different.
For the Monte Carlo guys, the direct-fit CARB is over $1000, but the Fed Compliant direct-fit is $212 (5 year warranty). #93940
Depending on how often you drive the car, spend accordingly on a new converter if it needs it. Converters weren't designed to last forever. There's a finite amount of conversion materials in one, so you have to spend accordingly.
Likely you had/have a dual bed converter on the Regal. You can tell as it has an A.I.R. inlet port from the A.I.R. system on it that goes right between the beds. So that's going to cost more. The issue with most engines in the 80s is that they were designed and developed in the 60s or 70s before emissions was a consideration. So converters had a lot to clean up. Later, engines were designed to burn cleaner and more efficiency (and a benefit to that came extra HP) so catalytic converters did not have to be of the same design, as well as engineering advancements on those as well. But 40 years is asking a lot from a cat converter. Mainly more for mileage than age, obviously, but I've seen rust get to stock converters as well.
I think this one is stock replacement for turbo regal from Magnaflow and is a dual-bed. #93439. I've never used any aftermarket ones, but have never heard anything bad about them. $312 for the Federal compliance one, but you'll probably never replace it again in your lifetime I would imagine. But it does have a 5 year warranty, whatever that entails.
For those with Olds V8 engines, Magnaflow makes a direct-fit Fed Compliant dual-bed for $157 (2 year warranty). #23427
The CARB compliant California universal job is nearly $700. (5 year warranty) California is always the pimple on America's azz and has to be different.
For the Monte Carlo guys, the direct-fit CARB is over $1000, but the Fed Compliant direct-fit is $212 (5 year warranty). #93940
Unless you "borrow" or "liberate" them from another car & take them to your local scrapper.
You can buy used cat converter mounting bolts but they usually come still attached to a old converter.
On the dual bed cats, don't worry about matching the inlet pipe to the cat or get a direct replacement that might be more than a simple cat. You can use the bung kit with out welding or have an extra 02 bung welded in to the exhaust pipe (inlet) that is going in to the cat. Most of the stuff in the 80s was still trial and error somewhat.
The forced inlet air is to oxygenate the exhaust to get a better burn in the cat. This was to reduce un-burned hydrocarbon. The process changes the incoming HC to H20 and CO2 exiting. At least that was the idea.
The forced inlet air is to oxygenate the exhaust to get a better burn in the cat. This was to reduce un-burned hydrocarbon. The process changes the incoming HC to H20 and CO2 exiting. At least that was the idea.
Since the OP never stated which way he's going with his car (whether wanting stock parts or modified), we can only guess.
In the 80s, the then-current dual bed 3-way cats like you'd find on Monte SS and Turbo Regal, 442, etc., had 2 working chambers separated by an empty air chamber. It reduced NOx in the first chamber, while the air chamber separated the beds. It didn't need the extra O2 in the first chamber to convert the NOx. The smog pump would pump air to the cat into the middle, or air chamber. This would add the extra O2 to help burn the unburned hydrocarbons and converted Carbon monoxide to CO2. So, theoretically the goal, what came out of the "cleaned" exhaust was N2, CO2, and H2O. This is why the cat of this type actually needs that extra air to work properly.
If you buy one of those newer types, you probably won't need the extra air as they're designed to deal with all 3 concenrns simultaneously. If you don't care about originality, you can ditch the smog pump and get one of those universal non-A.I.R. cats.
In the 80s, the then-current dual bed 3-way cats like you'd find on Monte SS and Turbo Regal, 442, etc., had 2 working chambers separated by an empty air chamber. It reduced NOx in the first chamber, while the air chamber separated the beds. It didn't need the extra O2 in the first chamber to convert the NOx. The smog pump would pump air to the cat into the middle, or air chamber. This would add the extra O2 to help burn the unburned hydrocarbons and converted Carbon monoxide to CO2. So, theoretically the goal, what came out of the "cleaned" exhaust was N2, CO2, and H2O. This is why the cat of this type actually needs that extra air to work properly.
If you buy one of those newer types, you probably won't need the extra air as they're designed to deal with all 3 concenrns simultaneously. If you don't care about originality, you can ditch the smog pump and get one of those universal non-A.I.R. cats.
I know you alluded to it, I just clarified it more where I know people complain about having to pass emissions but yet make their AIR pump inoperable, and then wonder why their tailpipe emissions are still too high. Likely the AIR pump was actually needed in their case and they weren't putting 2 and 2 together. Stock 80s technology cats NEED the AIR pump system to work correctly. Of course, if the cat's fried, that's a story for another time.
I know it's so tempting to yank that AIR junk off an smog engine, but unless you're going to compensate for it or you live in a non-smog testing area, I advise against it.
Similar threads
