Hi Guys, I got an 01 Discovery SE7 with the P0150 and P0174 Code. I searched online already but it seems my car is not a 02 or maf problem.
Heres the main problem, Bank 2 O2 (passenger side b4 cat) reads lean, but the exhaust smells very rich. But I still replaced the O2(bank 2 sensor 1). On top of that, bank 2 fuel trim is at 99 %, but Bank1 is completely normal. If the Maf is bad, I suspect both bank would go rich. However in this case, only bank 2 seems to be wrong. after I replaced the O2, it did not solve the problem, it still runs rich but the o2 gives a lean signal. BTW, when I took out the old O2, it ar dark as used engine diesel oil.


I read on this forum (http://www.lrrforums.com/showthread.php?t=7324) that theres a stepper switch in this thing that gets plugged up. is this a common thing?

Thanks for your reply, I hope I give you guys enough information.