Catalytic Converter replacement

BrianEsser wrote:

Or just not replace it at all, and use straight pipe.. *cough*

Brian is right on this1. Why bother spending money on a Cat that will just plug up down the road anyway? Just straight pipe it through and you don't ever have to worry about it. You don't have any downstream O2 sensors to worry about so it won't be a problem there, and you'll have as good if not better flow rate.

Bottom line its cheap, its easy, and it works. Don't worry Al Gore won't find out about you.

Hometown Hero wrote:

BrianEsser wrote:

Or just not replace it at all, and use straight pipe.. *cough*

Brian is right on this1. Why bother spending money on a Cat that will just plug up down the road anyway? Just straight pipe it through and you don't ever have to worry about it. You don't have any downstream O2 sensors to worry about so it won't be a problem there, and you'll have as good if not better flow rate.

Bottom line its cheap, its easy, and it works. Don't worry Al Gore won't find out about you.

...they plug up only if you misfuel/poison the cat or detune the engine.

Albertj

That's what engines do as the miles pile on. They wear out and because of that they are in essence detuned.

Hometown Hero wrote:

That's what engines do as the miles pile on. They wear out and because of that they are in essence detuned.

not at all. The computers adjust for mixtures being off, and a wide range of variables. The engine's tune is always being corrected as things change. Besides the only thing you really lose over time is compression, which is accounted for in mixture adjustments. If you are burning so much oil or coolant that you clog your cat, it's time for some engine work anyhow. A stock cat should be good for a few hundred thousand miles if the engine is running properly. There are cases where cats have failed/plugged, but there could be other underlying problems, and for the most part cats aren't replaced due to failure very often.

I recommend keeping a cat so you don't add to the pollution problems we already have.

So your saying engine wear has no affect on performance what so ever soleley because of your ECM? Thats just sounds bizarre, I understand what your ECM does, but I also understand that everything has its limitations. 1 has to ask themself why the cat needs replacing?

If your computer corrected everything to a "T" then in a perfect world your cat should not fail at all. My point isn't that Cats are bad and you don't need them. Rather my point is eventually they do plug up (no matter what your ECM does to compensate). Something a straight pipe will never, ever do. Your ECM will still compensate with the straight, but without the worry of having to replace it again.

Straights also save on cost per unit, and if your worried about hydrocarbons??? Honestly guys you see smoke billowing out of factory stacks, old POS cars that burn a litre of oil per block, the oil spill in the Gulf. Yet your worrying about your Rivs damage to the environment, but you still want a 350 whp Riviera? That doesn't compute. If you were really worried about pollution we'd be on a smart car forum not a Riviera forum.

Actually, cats rarely plug up... The original pellet-type converters flowed lousy from the start, and only got worse from there. But the ubiquitous honeycomb type that we have had for the last 15 or 20 years generally just wears out chemically before it plugs up. The exception would be an engine that was well and truly shot, or an SES light that was ignored, that resulted in a ton of carbon into the cat, or else ran so lean that the substrate melted.

And yes, Derek is basically right. The government insists on OBD, and parts rated at 100,000+ miles, solely for emission control - not to make life better for the owner/tuner/mechanic...

I'll have to take your word on the ECM compensation part.

But my car runs just fine with the straight (better than the cat I might add), and it cost me about $5. Whats a cat cost? $150? Does your car run better with it? No. Does it provide anything to the driver but meeting emissions that will most likely be changed to eliminate people from driving anything 10 years or older? No.

So why bother?

I guess the question is why bother removing the cat if it works. It's not that restrictive, and it is a smog preventative. If you live in a city with air pollution problems, it makes sense to keep it on. You'd be amazed at what one person's decision is worth when you consider there are a million people faced with the same decision.

On the other hand, if you live in a rural area, and smog is not a concern, I can see how not having a cat is ethically sound. Although cat converters do remove the smog producing emissions and noxious fumes, the result is a lot of CO2 being released into the atmosphere. A car without a cat will produce less CO2 than one that is equipped. And if Al Gore is correct, CO2 is the long-term problem leading to global warming, so cat converters can actually be a bad thing.

Quote :

I recommend keeping a cat so you don't add to the pollution problems we already have.

[/quote]

The only error in that thinking is you can take every vehicle off of the road today and it will make nothing but a minuscule difference in the US's pollution. Automobiles are not the cause of pollution. Despite what the eco-tree huggers want you to believe.

Straight pipe it and be done with it and enjoy the better exhaust flow.

AA wrote:

. Although cat converters do remove the smog producing emissions and noxious fumes, the result is a lot of CO2 being released into the atmosphere. A car without a cat will produce less CO2 than one that is equipped. And if Al Gore is correct, CO2 is the long-term problem leading to global warming, so cat converters can actually be a bad thing.

It's so funny that you said that, Aaron - I had the same thought. Now that we've reduced the real smog down to almost zero, the greenies had to find something else to tax & regulate. So now it's CO2, which is the byproduct of perfect combustion! But if we put more carbon monoxide out the tailpipe, we'll put out less carbon DIoxide...

Yank a cat for the planet!!

I know Aaron is an animal lover, as am I, I just happen to hate Cats as does our Hometown Hero.

After all of this conversation and analysis regarding Catalytic Converters, I should not have bought a replacement one when I did my headers.
Could have put a 3 inch pipe and an emulator.

Our State removed the Dynomometers last year and now only hook up to the OBD port.
Their logic, which I think was good, is that the outright majority of the cars on ours roads are OBD ll compliant. They don't need the drive cycle sniffing the exhaust.
Garages were being forced to buy this expensive equipment from only ONE VENDOR, no choices. And the equipment failing so often and costing shitloads of money to maintain by the shop owner. And you, as the shop owner, could only call that particular company to send someone out to repair and recalibrate the machine, sometimes more than once a month. And you would wait days and lose revenue. In this State it was a scam from the beginning to the end.
It was a state Racket that somebody's Brother-in-Law got the contract over 20 years ago.
Thank God it's over for now. Until........................To be continued.