I whant to remove the cat on my car but I dont know if my check-engine light will come off. ohh almost forget! I'm using a mopar performance PCM.

Nope it won't go off. You can remove the O2 Sensors and fool the PCM but it is not trivial.

The O2 signal affects the Air, timing and fuel injector pulse time.

The PCM will go to a default setting with no signal from the O2 Sensor. (I'm not sure about what the mixture is rich -lean) The idea is that with an o2 sensor fault the car will operate but not optimally for reduced emmissions.

You can always take out the engine service bulb.

I whant to remove the cat on my car but I dont know if my check-engine light will come off. ohh almost forget! I'm using a mopar performance PCM.Why do you want to do this? There are high flow cats that are around $80 and will keep you legal for emissions.

Why do you want to do this? There are high flow cats that are around $80 and will keep you legal for emissions.
I want to install the fx long tube header and I dont know if a cat is good idea. also I live in florida where there is not emissions testing.

it makes it very rich it turns very spluggish and horribly un reseponsive.

I want to install the fx long tube header and I dont know if a cat is good idea. also I live in florida where there is not emissions testing.Get a high flow cat and extend the wires for the O2 sensor. I have seen this done and it works good.

Get a high flow cat and extend the wires for the O2 sensor. I have seen this done and it works good.
thanks..

The mopar PCM senses the upstream O2 sensor only, at least I'm pretty it does cause the AFX ones do. That means you can take off the downstream O2 sensor and not affect the car at all. It shouldn't mess up emissions either because it won't be throwing a code for a faulty sensor.