Cold Start Engine Exhaust Temperature Too Low
During the cold-start strategy the ECU monitors exhaust temperature to ensure catalyst light-off. The measured EGT remains below the target threshold within the allowed time - heat-up strategy is not effective. Causes include excessive heat loss, very rich mixture cooling the exhaust, or a faulty EGT sensor.
Affected components
- Exhaust gas temperature sensor
- Cold start strategy
Common causes
- High likelihood: Excessive heat loss between port and catalyst
- Medium likelihood: EGT sensor drifts low
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.