I've got an "02 Xterra 4x4 that is running poorly. I need a new catalytic converter. I have the understanding that it has 4 catalytic converters. I was told that it was the driver side cat, but i was never told if it was front or rear. How can i figure that out? Also would it be possible to delete 2 of the 4 cats, to make life easier on me if this were to happen again? Also if i delete 2 of the 4 cats will i still pass emissions? I also get the smell of burning oil after driving for about 20 minutes. The temperature also shoots up. Is this also because of the failing catalytic converter?