Problem, How do I tell if my catalytic convertor has gone bad? Just yesterday I went to leave the house and the motor just would not warm up, then after driving for about 3-5 miles it began to idle fine. The problem is I could not get to go over 50 mph and then it just begin to drop down to 10mph. Could this be my convertor. I am pretty sure it is not my tranny. HELP!!

 

a chunk of your cat might have broken loose and is clogging the outlet.

 

could also be you CPS failing. Not had this problem on a Jeep yet. But just replaced in my wifes Hyundai Sonata, same exact symptom as you describe.

 

my cat is broken and it just sounds like I have coins in my exhaust.
If its warmed up and I turn it off and then start it back up and let it idle. . it throws a CEL but once i turn it off. . it goes away.

its possible that you have a chunk blocking up your exhaust but it seems more like you have something more then just that

 

Depends. What color was your puppy before?