I got a protege5 03 and the engine light went on suposibly its p0421 warm up catalyc efficiency below threshould (bank 1)
It's that good?
What are the causes?
Can I drive my carfor daily basis?
Thanks for your help

Sip

I am no expert, but do take care of my car and if and when the engine light comes on (although mine indicates where the problem could be), I pay attention to it. It usually signifies trouble and probably shouldn't be driven for any length of time with the light on. If you don't heed the engine light then it could probably cost you a lot more driving it while there is a warning. Getting it in to be looked at is a good idea in my books.

Your catalytic converter may need replacement, although they just published some information on other components throwing a converter code. Have a mechanic perform a back-pressure test on the converter to see if your exhaust is flowing properly. If not, you're looking at quite a few hundred dollars to remedy the problem. If you live where emissions testing is required, then you will absolutely have to have this done.