I have the 3" Magnaflow carsound cat on my 2.2 and its not where the stock one used to be its further down the line right under the big heat shield however its a good 10" from where the stock one was and I keep getting P0420 or P0402 codes : Catalyst not working within established parameters. I was wondering if maybe its: 1. not hot enough being its further back and 2. Its too big for the engine. My solution to #1 was to get the heat wrap tape and do from the header to around the cat to keep it warmer inside the pipe and thus allow the cat to work more "optimumly." Think it will work/help?

 

if you have the cat down past the second oxygen sensor, it's going to throw those codes.

you need the exhaust to pass through the cat first and then flow over the rear o2 sensor

if you have though, there's a good chance it flows "too much" and isn't working enough. the heat wrap idea may help but I wouldn't put all my faith in it

 

The cat has a pre-threaded area for the 2nd 02 sensor and the header has one for the 1st one.

 

sounds to me like its flowing too much, heat wrap is a good idea but I Don't know if that will solve your problem or not.

 

^^^ yeah that's what I'm still thinking as well.

the wrap might help but I don't think it will solve it.

why did you oversize the cat like that?

 

I bought it from Gravana and they said that the 2.5" was more expensive then the 3" and I asked about it being to big and the guy said not to worry about it and it should be fine.

 

I'm Getting The 3'' For Mine Too

 

In my opinion, and what i plan on doing is buying the complete catalytic converter system thats on a cobalt ss/sc. I done some research and after looking, the ss has bigger pipe going into and after the cat compared to my 2.2L, not to mention its all oem stuff so no codes, and no voiding of warranties.

 

which magnaflow do you have? from what I've read on JBO, you must have the Magnaflow #94035 or else you will throw a CEL.

 

The one on the Gravana website.

 

I would advise against purchasing the exhaust system for the SS/SC.

It not only has a 3" downpipe, but has 2.5" piping all the way back until after the rear axle and slims down to 2.25".

Now I shouldnt' be talking because I've got a full 2.5" catback and will probably end up with 2.5" piping from the header back , but the SS/SC exhaust is a little too large for the 2.2.

 

your setup will also be taking advantage of the 2.5" piping though Ninja, where as 3" will be overkill unless the person is going with a turbo or supercharger setup