Oxygen Sensors for Nissan Altima (2019-2021) 2.5L Upstream

Direct-Fit Upstream Oxygen Sensor for 2019-2021 Nissan Altima

What it Does: The Upstream Oxygen Sensor monitors pre-catalytic converter exhaust gas Lambda on the 2019-2021 Nissan Altima to provide rapid air-fuel feedback to the ECU, restoring factory fuel trims and throttle response.

The Stock Nissan Altima Sensor Degradation

Under continuous high-heat duty cycles in the direct-injected PR25DD engine, factory upstream air-fuel ratio sensors face severe thermal stress, particulate accumulation, and soot fouling. Over time, internal zirconia ceramic elements experience response degradation and internal heater circuit failure. This leads to slow sensor response, delayed closed-loop transitions, erratic idle, reduced fuel efficiency, and diagnostic trouble codes such as P0130 or P2A00 on the L34 chassis.

The Engineering Solution

Manufactured to OEM telemetry specifications, this upstream oxygen sensor features a fast-acting ceramic planar element that reaches operating temperature in seconds for immediate closed-loop fuel management. Housed in laser-welded 304 stainless steel, it resists thermal shock, corrosion, and exhaust-stream vibration. Machine-rolled M18x1.5 threads ensure anti-cross-threading installation into the manifold bung, while heat-shielded PTFE wiring and factory-pinned weather-pack connectors integrate directly into the PR25DD engine harness without splicing.

Technical Specifications

Compatibility

• 2019 Nissan Altima S, SV, SL, SR, Platinum 2.5L FWD/AWD
• 2020 Nissan Altima S, SV, SL, SR, Platinum 2.5L FWD/AWD
• 2021 Nissan Altima S, SV, SL, SR, Platinum 2.5L FWD/AWD

Frequently Asked Questions

Does this fit the L34 Altima?
Yes, this is a direct fit for the 2019-2021 Nissan Altima equipped with the PR25DD engine in the upstream exhaust manifold location.

Will replacing this sensor turn off my Check Engine Light?
Yes, once installed and drive cycles are completed, replacing a failing upstream sensor resolves open-circuit and slow-response diagnostic trouble codes.

The Nissan Precision Standard

Direct-injected engines require millivolt-precise stoichiometry to protect catalytic substrates, stabilize idle vacuum, and prevent power loss across the variable cam timing band.