Neon o2 Sensor

[Cornelius Washington]

I have a '96 Neon SOHC with 158k miles. I had the upstream o2 sensor
replaced about 3 months ago. Now, I'm getting the code 21 again along with
52. Could the o2 sensor be bad this quickly and making the engine run rich
or could there be another problem that's causing the sensor to foul? I'm
losing approx. 10 mpg since this started happening. Any ideas are
appreciated.

Thanks,
Cornelius

 

[Daniel J. Stern]

I have a '96 Neon SOHC with 158k miles. I had the upstream o2 sensor
replaced about 3 months ago. Now, I'm getting the code 21 again along
with 52. Could the o2 sensor be bad this quickly

Yes, especially if a Bosch O2 sensor was installed.

DS

 

[mic canic]

code 52 is a running rich code which could indeed be caused by a new failed o2
sensor esp. if it's a bosch, get a factory one, a scan tool with a good data
stream would be something that you might want to get your hands on.
could be a few other things affecting it too