my car is putting out code "P0420" Catalyst System Efficiency Below Threshold (Bank 1) , now i tried resetting it but it goes back on after 20 miles... I dont have any cats so im not worried, but is the car actually slower now that its in "limp" mode? I do have the cel fix but it doesnt seem to stop it... any ideas? is fuel economy affected as well?

 

oh i thought it's automatically on limp mode when the light is on... The car doesn't feel any different with the light on or without, and damm, it pulls like a mother... jst wanted to b sure u know... haha she is baby...