Pigging Secondary Cats

[lotekinc]

Is there any argument for gutting the secondary cats while leaving the primaries and O2 sensor location? Will it most likely set a code? Pass NC sniff test?

[AB18]

How do you think its gona pass a sniff test with no cats?

[S4evr]

definetly wont pass a sniff test but if you get tested through the ecu like MA, then you can do the spark plug nonfouler method and probably pass.

[lotekinc]

How do you think its gona pass a sniff test with no cats?

Primaries still there....

[Tokin]

I think one of the biggest pluses of "pigging" the primary cats is getting rid of the immediate blockage after the turbo. There is a lot of heat and pressure from exhaust gasses that is clogged up right behind the turbo because of those restrictive cats.

I don't think gutting the secondaries (while leaving the primaries intact) is going to do nearly as well for performance, or most importantly for helping with turbo life.

[espo4442]

I think one of the biggest pluses of "pigging" the primary cats is getting rid of the immediate blockage after the turbo. There is a lot of heat and pressure from exhaust gasses that is clogged up right behind the turbo because of those restrictive cats.

I don't think gutting the secondaries (while leaving the primaries intact) is going to do nearly as well for performance, or most importantly for helping with turbo life.

Exactly what I was thinking, it woud be a lot more effective to piggie the primary cats

[mholme]

I think one of the biggest pluses of "pigging" the primary cats is getting rid of the immediate blockage after the turbo. There is a lot of heat and pressure from exhaust gasses that is clogged up right behind the turbo because of those restrictive cats.

I don't think gutting the secondaries (while leaving the primaries intact) is going to do nearly as well for performance, or most importantly for helping with turbo life.

I think you are confused as to which are which. The primary cats are the ones under the car. The secondary cats are the ones up by the turbo that get gutted or removed, often called warm up cats. These are the only ones that have O2 sensors reading the gases that go into them and is also why you get codes when you remove them. But everything else you said is true.

[Tokin]

I think I was using the same terminology as the OP. Thanks for clarifying though.

[mholme]

I think I was using the same terminology as the OP. Thanks for clarifying though.

Ok. Then maybe he's confused(or maybe I'm confused) But yeah running pre-cats in place while gutting the main cats would be a waste of time.