Emissions

P2298 — O2 Sensor Out of Range During Deceleration (Bank 2 Sensor 1)

Severity: medium Safe to drive

What P2298 means

The engine control unit watches the upstream oxygen sensor on bank 2 during deceleration fuel cut-off, when the exhaust should contain plenty of oxygen. If the sensor's voltage or current is outside the expected range at that moment, the ECU stores P2298 and turns on the check engine light. Bank 2 is the cylinder bank that does not contain cylinder 1.

Symptoms

  • Check engine light on
  • Rough idle, especially on V-type engines
  • Unstable idle speed
  • Possible increased fuel consumption
  • Hesitation or surging when lifting off the throttle

Possible causes

  1. Failed bank 2 upstream oxygen sensor, including its heater
  2. Damaged wiring or poor connection at the sensor connector
  3. Exhaust leak near the bank 2 sensor
  4. Intake air leak
  5. Rich mixture on bank 2 due to leaking or faulty injectors
  6. Faulty ECU (rare)

How to diagnose

  1. Scan for codes and freeze frame data, and note any other fuel trim or O2 sensor codes
  2. Watch live B2S1 data: voltage or current, response to mixture changes and heater status
  3. Inspect the sensor harness and connector for chafing, corrosion or heat damage
  4. Check the exhaust for leaks at and ahead of the sensor
  5. Compare short and long term fuel trims on bank 2 against bank 1
  6. Smoke-test the intake for vacuum leaks
  7. Check bank 2 injectors for leaking or poor spray pattern
  8. Compare bank 1 and bank 2 sensor behavior during throttle lift-off

Common fixes

  • Replace the faulty bank 2 oxygen sensor
  • Repair the wiring or replace the connector
  • Fix the exhaust leak
  • Find and seal the intake air leak
  • Clean or replace faulty injectors

Questions and answers

What does P2298 mean?

The upstream oxygen sensor on bank 2 reported a signal outside the expected range during deceleration. The cause can be the sensor, its wiring, an exhaust leak or a mixture problem.

Can I drive with code P2298?

Usually yes, for a short time. Fuel economy and emissions may suffer, and a long-term rich condition can damage the catalytic converter, so get it checked soon.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.