P247F: Exhaust Gas Temperature Out of Range Bank 2 Sensor 4

What it means

The EGT sensor at bank 2 sensor 4 reports a value outside its plausible operating range over time - typically a degraded element giving an offset that the substitute logic flags as implausible.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

Bank 2 sensor 4 measures exhaust gas temperature at its location in the exhaust system. The control module checks whether its reading remains plausible as the exhaust heats and cools; it stores P247F when the reading stays outside the expected range, which can happen if the sensor has drifted.

Common causes

Most likely first.

1. Aged or biased exhaust-temperature sensor
2. Damaged wiring or poor connector contact
3. Sensor contaminated or damaged
4. Exhaust leak near the sensor

Symptoms

• Check-engine light on
• Possible reduced engine power
• Possible increased fuel consumption

How to diagnose it

1. Record freeze-frame data and compare bank 2 sensor 4 temperature with other available exhaust-temperature readings under similar conditions to see whether it is consistently offset.
2. With the exhaust cool, inspect bank 2 sensor 4 and its connector for contamination, physical damage, corrosion, or loose contact.
3. Trace the sensor wiring near hot or moving parts and look for melted insulation, chafing, or damaged connectors.
4. Check for an exhaust leak near bank 2 sensor 4 that could distort the temperature reading.
5. Use scan-tool live data while the engine warms to see whether bank 2 sensor 4 responds plausibly, then test its circuit and sensor against the manufacturer's specification.

Common fixes

• Secure the bank 2 sensor 4 connector and repair damaged wiring.
• Repair an exhaust leak near bank 2 sensor 4.
• Clean or replace a contaminated or physically damaged sensor if serviceable.
• Replace bank 2 sensor 4 if its reading remains biased or out of range after circuit checks.

Can I keep driving?

If the engine runs normally and the warning light is steady, a short, gentle drive to arrange diagnosis is usually reasonable. Avoid heavy loads or sustained high speeds if power drops, since unreliable temperature feedback can affect exhaust-system protection and emissions control.