I have a 2001 Chev Prizm (Toyota Corrolla) with check engine light on. Using a Innova code reader, the DTC is P0171 which means system too lean (bank 1) and the monitor status EV flashes. I have been told to replaced the MAP sensor but there seem to be none. Anyway I erase the trouble code and was told to due a drive cycle which I think means to drive around for awile, shut off engine and drive again. After doing this and checking code reader, it displays no DTC's but the monitor status c, o, oh, ev flashes all the time.