Need to replace the failing cat on my 2009 MC Base, want to just go with a cat less setup if one exists. I see plenty for the S but unable to locate any for my base. Any suggestions?

 

Please don't do this. Your car will emit 10x the pollution, you'll have a check engine light permanently on, and you'll never pass an emissions test. All for what?

Are you sure your cat is failing? Any codes set?

I discovered on my wife's Subaru that a P0420 (catalytic converter below efficiency) can be caused by a leaking exhaust manifold gasket. All I had to do was tighten the nuts holding the exhaust manifold to the cylinder head.

Check what codes are set and then fix the problem. Could be a leak in the exhaust system or a bad oxygen sensor, both simple DIY fixes.

 

Yes it's definitely the cat. I just spent $6000 on a new cylinder head, valve cover, water pump, two oxygen sensors, alternator, and a host of other little Piddly items. I'm not interested in spending another $1200 on the cat and manifold and there are no inspections where I am located .

 

Magnaflow has a lower priced xat system here as an option: 48 state legal.

https://www.ecstuning.com/b-magnaflow-parts/direct-fit-exhuast-manifold-with-catalytic-converter/49028~mag/