What it means
The EGT sensor at bank 1 sensor 2 signal jumps or drops out intermittently — typically a connector or chafed wire near the exhaust manifold heat zone.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Bank 1 sensor 2 reads exhaust gas temperature downstream of sensor 1 in that bank, and the control module uses the reading to monitor aftertreatment conditions. It checks that the signal remains continuous as exhaust temperature and vehicle vibration change. P2085 sets when the downstream sensor’s signal drops out or jumps intermittently, often due to a loose connector or damaged wiring near the hot exhaust.
Common causes
Most likely first.
- Connector loose
- Connector with intermittent contact under vibration
- Harness routed against vibrating component
Symptoms
- Check-engine light
- Possible intermittent reduced engine performance
- Possible exhaust or emissions-system warning
How to diagnose it
- Read freeze-frame data and graph bank 1 sensor 2 EGT to identify whether the dropout occurs during vibration, load changes, or regeneration.
- With the exhaust cool, inspect the sensor 2 connector and downstream harness for looseness, corrosion, chafing, and heat damage.
- Check connector pin fit and circuit continuity while gently moving the bank 1 sensor 2 harness.
- Verify sensor power and ground, where applicable, against the wiring diagram and manufacturer's specification.
- If the circuit remains stable, test bank 1 sensor 2 for intermittent output with the manufacturer's procedure.
Common fixes
- Reconnect and secure the bank 1 sensor 2 connector.
- Clean or repair terminals with intermittent contact.
- Repair heat-damaged or chafed wiring and secure the harness away from vibration.
- Replace bank 1 sensor 2 if it continues to drop out with a sound circuit.
Can I keep driving?
Gentle driving is generally reasonable if there is no power loss, but avoid heavy load if an emissions or performance warning appears. The intermittent downstream reading can interfere with aftertreatment monitoring and regeneration.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.