I have an '03 Explorer with a check engine light on. The code says "Bank 2 too lean" The vehicle runs fine in town, but on the highway, going up hills and when I pass, the engine downshifts fine but the speed does not increase. Also in this case, the engine pings. I would only get about 12 mpg on the highway.

I checked everything for vacuum leaks and found none. One shop said I had a bad Catalytic converter which I doubt. Another shop said the cat is good, but it needs a new O2 sensor before the cat.

Wondering if anyone has had similar problems

Jay

 

My understanding with the newer models (I just have old stuff!) is that if you had a vacuum leak you'd get a lean indication on both banks (code P0171 an P0174 as I recall). I've read somewhere you can test O2 sensors, but I haven't actually done it. You might be able to search the forum or the internet on procedure.