P244B: Diesel Particulate Filter Differential Pressure Too High (Bank 1)

P244B is a emissions-related diagnostic trouble code classified as high severity. When your vehicle's ECU detects this condition, it stores P244B and illuminates the check engine light.

If your vehicle has triggered P244B, you may notice one or more of these symptoms:

• Check engine light
• Noticeable loss of power and slow throttle response
• DPF warning light or message on dash
• Engine running rough at idle or under load
• Black smoke from exhaust under acceleration
• Higher fuel consumption
• On severe blockage: limp mode with reduced engine power

Here are the most common causes of P244B:

Generally yes, for short-term driving. Drivable in the short term, but treat as a priority repair. A heavily clogged DPF restricts exhaust flow, causes loss of power, can damage the turbocharger, and on some vehicles triggers limp mode after several drive cycles. Repair within days, not weeks.

Follow these steps to pinpoint the root cause of P244B:

1. With manufacturer-level software, read the DPF soot mass, distance since the last regeneration, the count of completed regenerations and the current differential pressure (a generic OBD2 reader cannot show these on most cars). A high soot mass with no recent regeneration points to an overloaded filter; the threshold that counts is the one for that vehicle, not a universal figure
2. Before any parts replacement, have a forced regeneration run with manufacturer-level software (a generic OBD2 reader cannot trigger one). A successful forced regen brings the calculated soot mass back down below the threshold for that vehicle and can resolve P244B without further repair, especially on a vehicle that has been driven on short trips
3. If forced regeneration fails or the soot mass refuses to drop, the DPF is either physically damaged or so loaded that off-vehicle cleaning is needed. Off-vehicle cleaning usually takes 1 to 2 days at a specialist and costs far less than a new filter
4. With manufacturer-level software, compare the differential pressure reading to the manufacturer specification at idle and under load. A reading that is high at idle but normal under load points to a faulty sensor rather than a clogged filter. The sensor is far cheaper to replace than the DPF
5. Inspect the DPF substrate with a borescope through the inlet flange. A cracked or melted substrate is visible and cannot be cleaned, only replaced. Catastrophic regeneration events (often after a misfire or rich condition) destroy the substrate
6. Confirm there is no downstream restriction by checking the exhaust system from DPF outlet to tailpipe. A collapsed muffler or crushed pipe section will mimic a clogged DPF

Repair costs for P244B vary depending on the root cause and your vehicle. Here are typical estimates:

P244B behaves differently depending on your vehicle. Select your car below for model-specific causes and known issues:

These codes are often seen alongside P244B or indicate related issues: