I was wondering if the third cat have a censor? I have just remove the third cat from the exhaust system so I can make it free flow from the manifold to the outside. And now I was wondering if the check engine light will appear? Am I going to have any problem without the THIRD cat out of the system? ???

shouldn't have any problem

if it is the cat closes to the back of the car, then no problem. I did it with mine with a high flow dynomax cat and it runs like a champ. and no light of course

The third cat, is really a resonator(I think), anything after the O2 sensor should not cause a CEL.

I have no CATs and no problems.