2001 Toyota Highlander Q&A
2001 Toyota Highlander Question: ENGINE MONITORS
The engine emission control module runs "monitors" to check certain components of the emission control system. The monitors need to be run and flagged as complete before your smog check will pass. The monitors are cleared when the computer fault codes are cleared or the 12v battery goes dead or is disconnected. A combination of city and highway driving over the course of a few days totaling 50-75 miles should reset the monitors to pass the smog check. Ask your smog check technician to check and see if your monitors are set before the next test is run just to be sure. - Russ
My car got rejected yesterday b/c the OBD monitor is reading "not ready" for all sensors. The check engine light has never come on since I've owned the vehicle. Could this be a low battery issue?
I was having P0171 & P0174 codes for Air/fuel to lean. Saw where Mass Airflow sensor is normal cause. Changed the Sensor now I am getting P0172 & P0175 codes for air/fuel to rich and car is not idl...
Parts available give me two choices. O2 sensor and Air Fuel Ratio sensor. Which is it? Location is Front manifold pre cat.