Any ideas? I did use an inexpensive O2 sensor. Should I just bite the bullet and get OEM? Could it be something else?

 

Did you replace the right sensor? My info is the code refers to the sensor *after* the converter.

Did you clear the code after you replaced the sensor? The code won't clear itself until the engine has gone through several warm up cycles.

P0036 refers to a heater circuit problem. Assuming you replaced the right sensor and the replacement sensor is acceptable -- always a bit of a gamble: I' have always subscribed to using OE senors when replacing O2 sensors -- there could be a sensor connector problem at the wiring harness or a wiring problem or even -- very rare -- a problem with the engine controller.

Here's a link to something you might find of value:

https://www.obd-codes.com/p0036

 

Yes, I did replace the sensor behind the cat.

I cleared it using a Schawen OBDII tool. Started the car, no code. But as soon as I turn it off and restart, it comes back on. I drove it on the highway to bring it to full temp. Same results.

I did place an order for an NTK sensor from ECS (I read that Bosh might be problematic, but mostly on forward sensor. Still, just in case).

I am going to replace it this weekend (along w (unrelated) compressor, accessory belt, dryer and power steering fan). Hopefully that takes care of the problem.

Thanks for your help.

 

We see issues with Bosch and other aftermarket 02 sensors all the time so I would get an OEM or NTK. We keep both in stock
https://www.waymotorworks.com/ngk-o2-oxygen-sensor.html

 

NTK Sensor did the trick. Wasted $24 on the cheap Chinese POS sensor.