I recently changed the crankshaft position sensor because i was having power trouble.The sensor was melted to the block it fixed some of the problem.My car still loses alot of power going up hills.
The code i get is P0420(Catylist System Efficiency Below Threshold) is this a sensor or catylitic converter?

Thanks for any advice you can give.

 

p0420 could be a bad catalytic converter,a weak o2 sensor,exhaust leak, the mechanical condition of engine(bad plugs(had a 99 contour give that code ended up being #1 plug faulty was a new plug) wires etc).