Walker Products 250-25120 left oxygen sensor for the 2018-2020 Audi A4 4-cylinder 2.0L and other vehicles measures the oxygen content of the exhaust gas. This Walker Products oxygen sensor is made for its specific application and fitment position, and it sends the engine computer the feedback it needs to track combustion efficiency.
- Measures oxygen levels to help fine-tune the air-fuel mixture and fuel economy
- Coating protects the electrode surfaces from contamination and erosion by combustion residue and particulates
- Electrodes are coated with a gas-permeable platinum layer
- Monitors exhaust gases to help reduce pollutants
Quick facts
- Part: Walker Products 250-25120 oxygen sensor
- Fits: 2018-2020 Audi A4 4-cylinder 2.0L and other vehicles
- Position: Upstream left
- Condition: New
A failing sensor can show up as rough running, higher fuel use, more exhaust emissions or a malfunction indicator light, and other faults can produce the same signs. With the engine off and cool, look over the sensor, its wiring harness and the connector for physical damage, since damaged wiring can shorten the sensor's life.
Fits
This sensor is a direct-fit replacement for vehicles that include the 2018-2020 Audi A4 4-cylinder 2.0L, the 2013-2014 Volkswagen Jetta 4-cylinder 2.0L and the 2019 Audi A4 Allroad 4-cylinder 2.0L.
Specifications
Fit and size
- Position: upstream left
- Quantity per vehicle: 1
- Thread: M18 - 1.5
Build and materials
- Type: wide-band
- Electrodes: gas-permeable platinum layer
- Condition: new
In the box
One oxygen sensor for the upstream left position. Each vehicle it fits takes one in that position.
Product information is for general reference and may contain errors. See our Disclaimer.
Frequently Asked Questions
Is this the right oxygen sensor for a 2018-2020 Audi A4 4-cylinder 2.0L?
Yes. Walker Products 250-25120 is the upstream left oxygen sensor for the 2018-2020 Audi A4 4-cylinder 2.0L. If your car is a different one, look it up in the "Vehicles it fits" section.
Is this the oxygen sensor for a 2013-2014 Volkswagen Jetta 4-cylinder 2.0L?
Yes. This upstream left sensor fits the 2013-2014 Volkswagen Jetta 4-cylinder 2.0L, and that engine takes one in this position.
What is the coating on this oxygen sensor for?
The coating prevents contamination and erosion of the electrode surfaces by combustion residue and particulates in the exhaust gas. The electrodes are made of a gas-permeable platinum layer.
Can a failing upstream oxygen sensor turn on the check engine light?
Yes, a failed sensor can light the malfunction indicator light. It can also appear as rough running, higher fuel use or more exhaust emissions, and a shop's scan can read the stored fault codes.
What does this Walker Products oxygen sensor measure?
Walker Products 250-25120 measures the oxygen content of the exhaust gas, which tracks the air-fuel ratio for combustion efficiency. The reading goes to the engine computer as diagnostic feedback.
