Everything I'm reading is telling me the heated 02 sensors l/r all throw CEL's when malfunctioning. The dealer has told me all of mine are dead, and I think I agree with them(after looking the the huge gaping hole in my first pre-cat.)

So, is there any particular reason why, the CEL might not being up? Could the previous owner by-pass these to avoid fixing a problem?

Any ideas or thoughts are appreciated,
Tactics

same problem here, after i did the ecu test... i thought after i reset it the CEL will still be on, but it didn't show up for the next 2 months... driving has been fine... so i don't know if the ecu is forealZ or not... need some help here