P2428: Exhaust Gas Temperature Too High Bank 1
Do not keep driving
Reduce speed, avoid heavy load, and get this looked at promptly rather than finishing the journey as planned. Exhaust temperature above design melts particulate filter substrates and damages turbochargers, and those are expensive parts that fail quickly rather than gradually. Do not park over dry grass or leaves — an over-temperature exhaust is a genuine fire risk, which is why handbooks warn about this after a filter regeneration. If a burning smell or visible smoke appears, stop somewhere clear and safe. The cause is usually something upstream putting fuel where it should not burn, such as a misfire or a regeneration that never completes, so ask what else is stored alongside it.
What this code means
Exhaust gas temperature on bank 1 has exceeded what the module will accept. This is one of the few emissions codes that is about immediate physical risk rather than about compliance.
What is at stake. Modern aftertreatment runs hot by design — a particulate filter regenerating deliberately raises exhaust temperature to several hundred degrees to burn accumulated soot. That is normal. What this code reports is temperature beyond even that, and the things it damages are expensive and quick:
- The particulate filter substrate can melt or crack, which is a large bill and cannot be cleaned out afterwards.
- The catalyst can sinter, losing its surface area permanently.
- A turbocharger sitting in that gas stream is being cooked along with everything else.
- There is a genuine fire risk. Vehicle handbooks warn against parking over dry grass or leaves during or shortly after a regeneration for exactly this reason, and an exhaust already running above its design temperature makes that warning more pressing rather than less.
The usual causes are upstream and are about fuel arriving where it should not burn:
- A regeneration running too long or too often, because the filter is not clearing — so the underlying fault is the filter or the sensor watching it.
- A misfire, dumping raw fuel into a hot exhaust where it burns outside the cylinder. This is the same mechanism that makes a flashing engine light mean stop.
- Late or excessive injection, including a leaking injector.
- A faulty temperature sensor, which is the harmless explanation and should be confirmed rather than assumed.
Marked not to be driven because unlike most emissions faults, continuing costs components rather than compliance — and the damage accrues under load, which is precisely when people press on.
Likely causes
Start here
- Incomplete particulate filter regeneration · specialist
- Engine misfire · moderate
- Leaking fuel injector · moderate
Less common
- Faulty exhaust gas temperature sensor · moderate
- Blocked diesel particulate filter · specialist
- Incorrect injection timing · specialist
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
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