So your 1500 has 2 cats? Mine had the same setup as described for your 2nd gen; one pre cat and one after. But did you have the sensors in a single pipe before they were connected? Would that be fine to do?

 

Yep, '04s went to 2 cats, one on each side before the factory "Y".

If you are omitting the cat, you can put both sensors in a single pipe, but you are going to have to change the exhaust air between the two to simulate it went through a working cat or it will pop a CEL immediately. I think they still sell "sims" for around $100 or you can do the simple $5 non-fouler trick (search the FAQ section for a DIY on using non-foulers)...

 

Yeah I've already done the non fouler trick. But putting both sensors in one pipe will work? Because it will only be getting half of the exhaust flow

 

Oxygen sensors measure the ratio of oxygen not the total flow through the pipe.

From http://en.wikipedia.org/wiki/Oxygen_sensor

 

Yep, what's gonna throw a CEL is when there is no change in exhaust gases between the two sensors which is why you use the non-fouler, to get the rear sensor more out of the exhaust flow. The resulting cleaner exhaust appears that a cat is in place and doing it's job...