Check Engine Light on 02 Forester w/ 90,000

subaru
engines
lights
forester

#1

Engine light came on two weeks ago. Had the code read at Advance Auto Parts. Code = P0420. The only performance issue was that it stalled when I started it the other day for the first time since I bought it last fall. Are there any other clues to tell what it could mean (catalytic converter vs. 02 sensor vs. anything else)? Is it really worth trying some kind of catalytic converter cleaner product?


#2

Link To Code Help:

Home page link - PO420 is a Top Ten requested DTC:

CSA