The other day, I loosened my radiator cap and forgot to re-lock it. About 10 mins into my drive home, my CEL came on (and about 2 mins later, I went "DOH!")
The code is the always super helpful and easy to chase P0420. I read that one of the causes can be "Faulty engine coolant temp sensor." Obviously, the cap is now back on, but I've only driven it on one 2-mile trip, so the light is still on. Is it worth it to start pulling O2 sensors/doing other diagnostics, or is this the likely cause?
Note: The engine did not overheat, or really even run that hot according to the temp gauge. (It was about 25 degrees outside).
1996 Chevy S-10 4.3L -- 185k