Previa error code #21

[choiss]

I got Check Engine lamp on, and wanted to read the error code. Autozone reads code for free, but mine is `92 Toyota Previa, and they could not read mine (They reads engine codes for the autos not older than `96).
Other garages charge a lot the for reading the code. So I went on and read the Chilton's service manual to learn reading the code.

My code was #21 and the causes include; Main Oxygen Sensor Signal or Main Oxygen Sensor Heater. Troubed areas, according to the manual, are Oxygen Sensor Cercuit, Main Oxygen Sensor, ECU, or Main Oxygen Sensor Heater.

The car runs good.

Should I replace the sensor? Or should I check into somthing before chaning it?

Thanks in advance for your help!

[mustang67408]

Originally Posted by choiss

I got Check Engine lamp on, and wanted to read the error code. Autozone reads code for free, but mine is `92 Toyota Previa, and they could not read mine (They reads engine codes for the autos not older than `96).
Other garages charge a lot the for reading the code. So I went on and read the Chilton's service manual to learn reading the code.

My code was #21 and the causes include; Main Oxygen Sensor Signal or Main Oxygen Sensor Heater. Troubed areas, according to the manual, are Oxygen Sensor Cercuit, Main Oxygen Sensor, ECU, or Main Oxygen Sensor Heater.

The car runs good.

Should I replace the sensor? Or should I check into somthing before chaning it?

Thanks in advance for your help!

Yes, replace the main oxygen sensor.
Please do not use a universal one or a Bosch one, they just don't work properly MOST of the time.
Get a FACTORY TOYOTA one.
Pm me for details if interested.