Positioned at one or more points along the exhaust system — typically before and after the diesel particulate filter or catalytic converter — the exhaust gas temperature sensor feeds real-time thermal data to the engine management unit. That data allows the ECU to regulate regeneration cycles in DPF-equipped diesel engines, protect the catalytic converter from overheating, and trim fuelling strategies to stay within safe operating limits. When an exhaust gas temperature sensor fails, the ECU loses a critical reference signal and often defaults to a conservative operating map that triggers a warning light and, in many cases, locks the vehicle into limp mode. A sensor that reads low forces overly rich regeneration attempts that can crack the DPF substrate; one that reads high may abort regeneration prematurely, leading to DPF blockage within a few thousand miles. Sensors are particularly vulnerable on high-mileage diesel engines that have completed frequent short journeys, because repeated thermal cycling fatigues the sensing element over time. Confirming the OE number is important because sensor positioning, connector type, and thread pitch all vary by application. CASCO and Meat & Doria both offer sensor ranges that cover the majority of European diesel applications, with references mapped directly to OE part numbers for precise fitment.
Exhaust gas temperature sensors are application-specific: the same model line may use different sensors at position 1 (upstream of the DPF) and position 2 (downstream), with different connector housings and thread sizes at each location. The OE number encodes all of these variables. You can find the OE reference either from the sensor itself — it is usually printed on the body — or by using the make-model-engine selector on this page. Matching position and connector type is just as important as matching the thread, so always confirm both when ordering.
OEM sensors are calibrated to the vehicle manufacturer's tolerance band and carry the vehicle-specific OE reference. Aftermarket units from brands such as CASCO or Meat & Doria are manufactured to the same resistance-temperature curves and use the same connector materials. Lower-grade alternatives may drift from their calibration sooner due to inferior sensing element construction, causing the ECU to receive subtly incorrect readings that degrade emissions performance and accelerate DPF wear before a fault code is ever logged.
Yes, indirectly. If the sensor reports a temperature below actual, the ECU may inject additional fuel to trigger DPF regeneration when the filter is already hot enough, which can melt the substrate or crack the monolith. Conversely, an artificially high reading will abort regeneration early, causing soot to accumulate until the DPF blocks. In either case, the downstream cost — a replacement DPF or catalytic converter — far exceeds the cost of replacing the faulty sensor promptly when the dashboard warning light first appears.
A check engine light accompanied by fault codes referencing exhaust temperature circuit range or performance is the most common presentation. On diesel vehicles, repeated failed DPF regeneration attempts — indicated by the DPF warning light — can also point to a faulty sensor. You may notice increased fuel consumption as the ECU runs enriched mixes trying to raise exhaust temperature, along with a noticeable loss of power if the vehicle has entered limp mode. In extreme cases a strong smell of unburnt fuel from the exhaust accompanies the failed regeneration attempts.
Showing 100 of 4,939 Exhaust gas temperature sensor OE numbers. Enter the OE on the main OE search to jump to any reference.
