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Lanskpr
01-26-2011, 20:13
Pretty sure it has never been changed. At least since 2000. I have some of the records preceding that and no indication that it has been worked on.

Is that normal? I thought I have read that the Catalytic Convertor gets clogged up after awhile and impedes the exhaust gasses from escapeing.

More Power
01-27-2011, 12:56
Depending on how the vehicle is driven, and in what sort of climate, the cat can become clogged over time. Cold weather and short trips cause the cat to plug sooner than when driven in warmer weather and when higher demands are placed on the engine, like towing.

Cats are somewhat pricey. Those owners who live in states/locales that don't require emissions testing usually remove the cat. Those who have to have one to pass emissions testing can test it by drilling a 1/8" hole in the exhaust pipe just before and after the cat, to be used for a pressure gauge fitting. A new cat might produce about 1-psi difference under acceleration, while the cat should be replaced if you're seeing several psi difference. Simply weld the holes shut or thread in a machine screw to fill the holes afterward.

Jim

Kennedy
01-27-2011, 13:27
Opening up the exhaust on the 6.5 is one of the best things you can do. Emissions is the key. Most will pass the sniff test w/o issue cat or no, it's the visual that gets most. I've often said that your engine could be consuming CO and NOX and producing sunshine, moonbeams, and rainbows and they would still fail you hence the need for a "ghost cat" at minimum.

Lanskpr
01-27-2011, 21:29
Depending on how the vehicle is driven, and in what sort of climate, the cat can become clogged over time. Cold weather and short trips cause the cat to plug sooner than when driven in warmer weather and when higher demands are placed on the engine, like towing.

Cats are somewhat pricey. Those owners who live in states/locales that don't require emissions testing usually remove the cat. Those who have to have one to pass emissions testing can test it by drilling a 1/8" hole in the exhaust pipe just before and after the cat, to be used for a pressure gauge fitting. A new cat might produce about 1-psi difference under acceleration, while the cat should be replaced if you're seeing several psi difference. Simply weld the holes shut or thread in a machine screw to fill the holes afterward.

Jim

Thanks Jim! For the most part, it is operated in fairly warm climate with mostly short trips. Can this test be done while the truck is stationary? Can I just hold a rubber tip pressure gage on hole while throttling the engine?

Lanskpr
01-27-2011, 21:38
Opening up the exhaust on the 6.5 is one of the best things you can do. Emissions is the key. Most will pass the sniff test w/o issue cat or no, it's the visual that gets most. I've often said that your engine could be consuming CO and NOX and producing sunshine, moonbeams, and rainbows and they would still fail you hence the need for a "ghost cat" at minimum.

I get what you are saying about the exhaust. Will try to determine what shape the cat is in via test suggested by Jim. Just out of curiosity, what specific ingredients are required to get "moonshine" to spew from the tailpipe. I can do without the rainbows. Just thought this might be a good way to fund future modifications:)