Ok, I know if I take my A.I.R. system out and keep the cat, it could clog at some point in a rich running condition. Or so I've been told.

So, If I run a high flow cat could the same problem occur? Should I just say screw it and run a test pipe? Let me know your thoughts, as far as emissions is concerned I have ways of passing without the cat, BUT, if I can get the same flow with a CATCO or something I'd rather be somewhat legal.

Thanks for the input.

 

The catalyst only works effieciently when there is a PROPERLY processed 14.7:1 air to fuel mixture. Any less then that will result in a clogging condition. Remember that the key ingredient in the catalyst process is oxygen. So to answer your question, if you run a cam which has too much overlap, or a very rich engine, it is only a matter of time until the catalytic converter becomes fully clogged. This will choke the life out of your engine. A high flow cat functions under the essentials as a OEM cat. I personally run with a catalyst on my car. I have a Catco High Flow Cat and my engine is properly tuned and have not experienced such problems as you describe. I dont know for sure when the clogging point occurs but, I have seen vehicles with 30,000 miles on them come into the shop with a clogged catalytic converter due to an improper functioning 02 sensor. I am not sure of how radical of a setup you are running but for near stock applications, sans injector changes, timing changes, and ECU reprogramming to name a few, you should be ok with a Catco High Flow Catalyst. Hope that can help you in your decision. -Bob

 

 

Well, my car runs a little rich anyway. So if I put a air/fuel ratio gauge in and make sure it's running relatively 14.7:1 I should get the same life out of a cat regardless if the A.I.R. if hooked up or not. If I understand correctly.

 

dont bother buying one of those air/fuel ratio gauges. there junk. the majority of the ones on the market, including the auto meter one, are usless for tuning your engine to the correct ratio. All your gonna see if a red/yellow/green light moving back and forth all the time. The gauge is being somehwhat accurate but the ECM is constantly making fast changes to achieve a certain air/fuel ratio that the gauges just sweeps back and forth as you drive. You nail the gas and it just reads pig rich like it is suppose to do. you left off and it goes the other way. Just dont think that by buying one of those gauges that you will be able to properly adjust your air/fuel ratio.

Go to a local dyno and get a few puls with a wideband O2 sensor installed. That wil give you a better idea on how your engine is running.

 

I thought the AIR was only used in the start up of the motor, to add O2 to the exhaust to help light off the cat, bring it up to temp quicker and minimize emmisions during that time....

And if our motors ran a perfect 14.7 all the time and perfect burn, then we wouldn't need cats. The only reason we have catalytic converters is to catalytically convert unburnt hydrocarbons right? So not running at 14.7 all the time shouldn't kill the cat...

 

what fills a cat is a constant rich condition I believe. Yes our cars dont alway run at a perfect 14.7:1. Your engine get a boat load of fuel when you hammer the gas no matter how many mods you have done to your car. Your AFR can be off a little bit and your cat should survive. And if you AFR is off a lot then destroying the cat is the least of your problems.

 

Correct, an engine does not always run at a constant 14.7: air to fuel ratio, due to the fluctuation of engine load and throttle application. The key to having an effiecient catalyst is to have enough oxygen present for the chemical reaction to take place. As oxygen is needed for a fire, a catalyst needs it to perform its function. The rich condition will dilute that air needed to perform the chemical reaction that turns HC and O2 to C02 and H20. When a CONSTANTLY rich mixture is present this throws off the ratio and can lead to catalyst failure. Hope that can help to clear up any misunderstanding. - Bob