could be : plugs, wires, egr, holes in intake track,fuel filter, cat,afm.
my car had 110,000 miles on it and the origional o2 sensor and it was shot to hell and my check engine light never came on. the error code was there but the light never came on. at autoshop101.com it talks about these ecu's and error codes and it also states the o2 sensor in older toyotas doesn't cause the check light to come on. only things that will cause severe drivability problems will trigger the light.Junkie said:O2 sensor will flash a check engine light at freeway speeds sometimes if bad,but will not make the car stumble.
My guess is your fuel pump is on it's way out.Have a similar problem with my Cressida right now.I have check all but the pump,as it's a PIA to do,and I haven't had the time or space to tear the car that far apart."I really don't want to pull the damn tank:lol: "
Do you mean earlier models or that O2 sensor stops working?at autoshop101.com it talks about these ecu's and error codes and it also states the o2 sensor in older toyotas doesn't cause the check light to come on.