OBD Code

[tyler2016]

I have a 2014 Jetta 1.8 throwing P2270, which is downstream O2 sensor stuck lean. It only has 32k miles. Warranty won't cover it. I haven't noticed a loss of power or fuel economy. The exhaust, fuel lines, and injectors look ok. The connector to the sensor in question is under a splash guard/aero panel. I haven't done anything other than inspect things. I am thinking I just need to replace that O2 sensor. Any other ideas? I have had the vehicle for about a year. It was formerly leased in New Jersey. Maybe salty slush got under above the splash guard and corroded the connector?

[zolotiyeruki]

There's a good chance it's just a sensor gone bad.  They do that.  As I understand it, that sensor is only used to monitor the efficiency of the catalytic converter, and doesn't affect how the engine is controlled.

[lthenderson]

Don't know if this will apply for you, but here in the Midwest where Ethanol blended gas is the norm, I had lots of problems with downstream O2 sensors over the years until I stopped using Ethanol blended gas. After I stopped, my O2 sensor problems went away.

They aren't very costly and if you have the right special socket, they are pretty easy to replace most of the time, especially on newer vehicles where they haven't had a chance to get frozen in place.

[dcheesi]

Just a note, I had a code for the downstream sensor and had it replaced, only to have the code come back after a week. Turned out that it was the upstream sensor going bad that was causing the downstream sensor to appear bad. (The upstream sensor is the one that's actually used to tweak the air/fuel ratio, so if it's reading wrong it can cause the downstream O2 levels to be wildly outside the normal range.)

[tyler2016]

Just a note, I had a code for the downstream sensor and had it replaced, only to have the code come back after a week. Turned out that it was the upstream sensor going bad that was causing the downstream sensor to appear bad. (The upstream sensor is the one that's actually used to tweak the air/fuel ratio, so if it's reading wrong it can cause the downstream O2 levels to be wildly outside the normal range.)

That makes a lot of sense. Upstream sensors on Rock Auto are on back order.

[kidmont]

I have O2 sensor problems too. It is happening from a couple of months. So, following thread, if I get more valuable information here. Although, I am thinking to buy obd2 scanners. This type of scan tool might help to find the problem.

[sequoia]

I have a 2014 Jetta 1.8 throwing P2270, which is downstream O2 sensor stuck lean. It only has 32k miles. Warranty won't cover it. I haven't noticed a loss of power or fuel economy. The exhaust, fuel lines, and injectors look ok. The connector to the sensor in question is under a splash guard/aero panel. I haven't done anything other than inspect things. I am thinking I just need to replace that O2 sensor. Any other ideas? I have had the vehicle for about a year. It was formerly leased in New Jersey. Maybe salty slush got under above the splash guard and corroded the connector?

Best advice I can give you is to find a forum for your car and do a search and ask for advice there. I would image there is at least one forum for Jetta since it is a pretty common car.

If you decide you want to replace the O2 sensor, Autozone or other local auto part stores will loan you the special socket for this.

[Dr.Jeckyl]

The O2 sensors are sometimes covered by the emissions warranty which would be longer than the bumper to bumper warranty. Different states sometimes even require longer than standard warranties on these parts. I would look up the emissions system warranty for you vehicle and your state to see if it is covered.

[AccidentalMiser]

I have a 2014 Jetta 1.8 throwing P2270, which is downstream O2 sensor stuck lean. It only has 32k miles. Warranty won't cover it. I haven't noticed a loss of power or fuel economy. The exhaust, fuel lines, and injectors look ok. The connector to the sensor in question is under a splash guard/aero panel. I haven't done anything other than inspect things. I am thinking I just need to replace that O2 sensor. Any other ideas? I have had the vehicle for about a year. It was formerly leased in New Jersey. Maybe salty slush got under above the splash guard and corroded the connector?

Gotta be a Jetta forum out there on the interwebs somewhere?

[tyler2016]

 I finally got around to fixing it. It was the downstream O2 sensor.