So last year my car threw up the following codes

O2 sensor Bank 1 Sensor 1
O2 sensor Bank 1 Sensor 2

Heating malfunction.

So i took it to a shop today, and they stated that it most likely is not the sensors, since 2 sensors in the same bank with the same problem is highly unlikely.

Not sure what to do, anyone ever had this problem??

Should i fix the sensors first, or should I look for somethign else?

 

Could be the ECU.

 

I mean, I bought my car with only 4 codes. All 4 02 sensors circuit malfunction. I cleared the codes, a minute later all four came back on. I went ahead and bought all 4 OEM Denso sensors from Rockauto, $50 and some change each. Installed, cleared the codes and after 3 years, I haven't seen a CEL on once.

They read circuit malfunction. Not engine running lean or rich. So I think you should replace both sensors. (Bank 1 sensor 1) is Upstream 1,2,3 and (Bank 1 sensor 2) is Upstream 4,5,6.

 

Had the P0141 bank 1 sensor 2 oxygen sensor code on my brother's GS300, bought the OEM Denso sensor from Amazon and replaced it and the CEL went away and passed emissions.

You might want to check conductivity of the O2 sensors with a multimeter first before replacing them:

 

So is P0171 bank one sensor 2?

 

I've had several issues with the O2 sensors over the years, but it was actually the MAF sensor. Replaced it with used one from eBay and cleared codes, no issues for 13k miles now and it drives much better. The O2 would throw, they'd clear it, it would stay off a few months, then back, then last time they said it was both sensors at a different place as I had moved. Replaced it a year ago..., but let them replace the first one and clear codes to see if both really needed replacing. Year later it needed replacing again??? Cleaned the MAF sensor, might've fixed it, used to use a K&N filter... don't recommend, just threw in the MAF sensor I bought years ago on eBay as a back up and haven't had issues at all almost 3 years now. The car would drive fine, but randomly had hesitation issues etc... when these sensors kept throwing codes even though they were not even the problem. Hope this helps or something to consider.

 

Good job on linking the video speedkar9

The specs for the O2 sensors are 11-16 ohms resistance by the way.