2ndary Air Injection= Cat Killer???????

[Fr8dawg98]

For those who have way more knowledge than I...

Secondary Air Injection system died. Replaced with blocker kit. What I know about this system it prematurely heats the exhaust gas to get rid of Hydrocarbons. Will this cause a premature death of the Cats?

With all that being said I have replaced both O2 sensors and still have a P0420 code. Looks like I will need to replace the cats. I don't want to spend this $ and have to replace the cats again later.

Also is there a way to diagnose which of the 2 cats has failed?

Thanks Fr8dawg

 

[MNGX]

[NOT AN EXPERT]

Having just done the bypass, I can at least relay what I learned.

The SAIS just sends warmer air from the top of the engine into the exhaust on cold starts so the cat heats up more quickly. It would have no impact whatsoever on the performance of the cat - the air that hits the cat in this scenario is certainly no warmer than on a summer day when the SAIS doesn't kick in.

Installation of the bypass module and plates just means the exhaust system will operate "normally." If the question is whether the fact that on cold starts the cats now get colder air than with the SAIS activated will damage the cats - I really don't think so. It just means the cats won't reach optimal levels of emissions-reduction efficiency as quickly.

As to figuring out which cat is bad, Here's this dude's walkthrough.

 

[Fr8dawg98]

Excellent. Thanks MNGX.
Fr8dawg22