is it better to keep it on or can i cut it of ? well it mess up the car with the back pressure you have to have or what should i do any suggestions help please ...

2nd Gear
test pipe.
I'm make believe
test pipe or have the inlet and outlet made to 3" on the stock cat. This will improve flow and still let you pass emissions. The stock cat is already a HF cat and barely looses any whp
I'm make believe
I edited my statement. I left out a few words that i guess confused you. I was talking about a modified stock cat section
2nd Gear
well depends on where you live. in cali, you wont pass smog unless you have an actual cat in it, but if you have quattro, find a place that doesnt have an AWD dyno like in folsom, and they just rev your engine so it doesnt get run under load. This makes it super easy to pass smog
1st Gear
i removed mine and put decat pipe on but have to remove and refit cat evry year for MOT test (UK) but the way i look at it a new cat is £300 here so not using it apart from when test is due saves it breaking and having an expensive bill.
dont mind if the decat pipe rots and needs replaced as they are cheap
dont mind if the decat pipe rots and needs replaced as they are cheap well i live in florida and theres no tests here but i just wasnt sure if its gunna mess the motor up with the back pressure without the cat ,so i can cut the cat out and the resinator out and have no problems