I have an 2008 3.0L and I was wondering if anyone knows if the 4.0L cats and the 3.0L cats were the same and would work on either or. I can’t seem to find anything saying if 4.0L cats would fit on the 3.0L or if they don’t just want to know so I don’t waste my money trying it out

 

the cats on my 01 3.0 are welded in. The Y pipe is one piece with the cats. Do you need then to pass smog?

 

Rock Auto shows different part numbers for the 3.0 compared to the 4.0 so the answer is no they are not the same.

Get quality units if you need to pass emissions and for them to last. Walker is a good brand.

Make sure you fix any issues with the emissions/fuel system first if thats what caused the cats to fail.

 

I was thinking of the cats not the Y pipe. Meaning that you would cut your old cats out and weld in new ones.