I have a 01 Mustang 3.8 v6. It has the Stage 1 Roush kit on it with the side exhaust... etc. My car starting running poorly lately, then got to where it wouldnt run at all, so I took my car to the Ford dealership. They told me my cats were stopped up and my car had the wrong computer in it. They said the computer in my car was for a 3.0l ford ranger, and it had a Superchip in it so that voided my warranty. He said that the computer was making my car run too rich, which stopped up my cats. My car only has 50,000 miles on it. It has the K&N intake and stock injectors so I dont see how it is running rich. My car ran great when I first got it. And I dont see how it could of got the wrong computer in it. Their trying to charge me $2500 to fix it, I was wondering could I just get the cats takin' off or just the front two and my car run fine again. People have told me that taking off the cats give you more hp and the car will still run fine, but the dealership told me taking them off will mess your engine up because you wont have any backpressure. I was wondering what should I do?