Yes the 2.7 sedans have 2 cats. They are mounted right off the manifolds.

Yes shelling it will cause a CEL. Adding the headers like mine also throws a CEL.

 

So I need to just replace them or wait until it throws a code. Thanks for the help

 

Ya. They're expensive. The dealerships I went to would only sell them as a pair with the y-pipe $800, and they'd only sell them if they installed them $450.

That's why I opted for the headers and CEL. I just stop in autozone once in a while and have the codes run to make sure nothing else is throwing codes.

 

Where did you pick up the headers? What do they cost? And can you fool the computer to make it not throw a code? Either spark plug defouler method or computer tune. I know I have a lot of questions but 11-12 mpg is getting a bit old.
Thanks

 

They were custom made and fitted by a shop in poynette, WI. (T&S Customs) $600. Most exhaust shops can do custom headers, cost is the biggest thing.
We tried defouler, and ecu retune. I still have a CEL.
However with my mods i average 28mpg. (most of which is town driving)
hope this helps.

 

It helps a lot! I apperciate all the answers. Thanks