Runnin without cats..is that bad?

[911GGSX]

I took my cats off just to mess around and the car ran ok before i did that. Now it idels and like 500 and almost stalls and when i give it gas it hesitates for about 3 seconds then just takes off. i have an auto trans and im pretty sure its not slipping. when i give it gas it goes to about 1500 rpm than jumps to about 4k. Is it because i took the cats off? anyone info would help. thanks

 

[David15151]

First, there is only one cat for our cars. 2nd, do you mean you just cut off the cat? and left it open like that? or put in a test pipe in place of the cat? 3rd, if you did the first option and just cut the cat off with an open echaust.. the engine problem is prolly due to the 2nd 02 sensor getting totally wrong readings then what is really going on as its just hanging there not getting much of the exhaust flow. This is of course assuming that you have a 2nd 02 sensor cause i know all the 2nd gens do.. not sure which car you have. This is about the best i can diagnose the problem.. exhaust should not have that kind of effect on a car unless like i said the 02 sensor is giving crazy readings and that might confuse the ECU and make it run bad. Did you do anything else besides this?