Hi there! I am trying to help my brother fix his 2003 express 1500 with the V6 engine. It keeps stalling out on him and he has a CEL with a fault for the bank 1 cat converter. If I take the O2 sensors out it runs fine (Although a bit loud ), so it looks like a failed converter.

My question is this - this van was originally from and equipped with California emissions, so I know the cat is different than the other 49 states. The van is now outside of California in Missouri and wont be going back. Do I have to put a California approved cat on it, or can I just weld in a good aftermarket unit from somebody like Magnaflow or use the OEM Chevy unit for 49 state use?

Thanks for the time and help!

 

You will be ok to install an aftermarket one as long as it is approved by the state of Missouri. As long as your brother does not plan to re-register the vehicle back in CA, there is no need to keep it CA approved. I hope this helps. California emissions are over the top if you ask me. I lived there for 32 years before I moved to Texas.

 

I am not 100% sure about this because we would never do that at work. The outside of a California looks exactly the same but the inside is not. Since California emission is more strict the computer is set up differently. I would be almost positive that you would end up with a converter efficiency code with in the first month and the have to replace again.

 

I don't think Missouri even has emission regs so you can probably cut that cat off and harvest the platinum.