دوده‌گرفتگی محل نصب سنسور

The drilling or boss that connects a pressure sensor to the manifold or exhaust, fouled with carbon so the sensor is isolated from what it should measure. The sensor is faultless and reports the pressure at its own port — which no longer changes.

A fouled port gives a flat, plausible trace, and that is the dangerous outcome: the value sits in range, nothing looks broken, and the module acts on a number that stopped tracking reality. A reading that barely moves between idle and load is the signature, and it is visible only if you watch the value change rather than read it once.

Manifold pressure ports foul with oil mist and recirculated exhaust; exhaust ports foul with soot. Clear the port with the sensor removed and inspect the drilling rather than the sensor — it costs nothing, and fitting a new sensor into a blocked port reproduces the fault exactly, which is how this becomes a repeat visit.