Ecm Lights Indicating Oxygen Sensor Problem

[FrankRX]

Hello All,

For an RX 300, I recently replaced an oxygen sensor that was diagnosed as being bad. After about 200 miles of driving, the check engine light still appears. Does this have to be reset or could there still be a problem? If it can be reset manually, how does one do it. I had the power (battery) disconnected but this did not reset .

[tjmc11]

Hello All,

For an RX 300, I recently replaced an oxygen sensor that was diagnosed as being bad. After about 200 miles of driving, the check engine light still appears. Does this have to be reset or could there still be a problem? If it can be reset manually, how does one do it. I had the power (battery) disconnected but this did not reset .

The engine computer will not ever reset without completely disconnecting it. You will need to have the code reset by a mechanic or a diagnostic tool. You are currently suffering cat inefficiency which is common at higher milage. The catylitic converter functions just above the efficient range and can sometimes dip below that range from time to time. A new sensor helps with this problem, but usually you can have the cat reset and the light will stay off for a long while unless the cat is really close to going out. You will need to get the code reset or the cat replaced if you are getting and emmissions inspection. Make sure they erase the code history as well if you take it somewhere to have that done.

[FrankRX]

Hello All,

For an RX 300, I recently replaced an oxygen sensor that was diagnosed as being bad. After about 200 miles of driving, the check engine light still appears. Does this have to be reset or could there still be a problem? If it can be reset manually, how does one do it. I had the power (battery) disconnected but this did not reset .

The engine computer will not ever reset without completely disconnecting it. You will need to have the code reset by a mechanic or a diagnostic tool. You are currently suffering cat inefficiency which is common at higher milage. The catylitic converter functions just above the efficient range and can sometimes dip below that range from time to time. A new sensor helps with this problem, but usually you can have the cat reset and the light will stay off for a long while unless the cat is really close to going out. You will need to get the code reset or the cat replaced if you are getting and emmissions inspection. Make sure they erase the code history as well if you take it somewhere to have that done.

[tjmc11]

Frank,

Let me know if you need any additional help. Hope you have discovered the problem and are able to fix it soon.

[Grumpa72]

Hello All,

For an RX 300, I recently replaced an oxygen sensor that was diagnosed as being bad. After about 200 miles of driving, the check engine light still appears. Does this have to be reset or could there still be a problem? If it can be reset manually, how does one do it. I had the power (battery) disconnected but this did not reset .

You can borrow the tool from Auto Zone or Advance Auto and reset your OBD II system right there in the parking lot. Takes all of five minutes, most of that will be trying to figure out the OBD scanner. Disconnecting the battery won't do anything except lose your radio codes and seat memory.