Ref: 1991 Camry V6 2.5L 2VZ-FE engine, 63,551 miles driven. Failed CO
emissions in downstate New York, on Wednesday.
Vehicle taken to Toyota dealership on Friday for diagnosis.
No CHECK ENGINE light was lighted and no stored codes were found in
the ECU. The O2 sensor signal does not fluctuate, stays at 0.68 volts,
and resistance measured as 12 ohms.
It seems that there is a hard failure of the O2 sensor, and yet no
engine trouble codes were found stored in the ECU memory.
At what temperature must the exhaust gases reach prior to testing an
O2 sensor on this vehicle?
While at the dealership, the vehicle was not put on a
dynamotor. The above test results were reported by the technician.
Is O2 sensor testing normally done after running vehicle on a
dynamotor to get components/exhaust gases up to proper temperature ?
Sensor is now on order via dealership service shop.
Service Advisor recommended that emissions re-inspection be delayed
after replacing the O2 sensor a couple of days to allow for "break
Is a break in period applicable/required for an O2 sensor?
I have read that a CAT needs a break in period.
Do you agree that the re-inspection should be delayed ?
~ Vince ~