Mazda B4000 EGR Pressure Feedback Sensor Replacement Cost

The EGR pressure feedback sensor is used to monitor pressures in the exhaust gas recirculation system, part of the vehicle's emissions control system. With this sensor, the engine control module, or powertrain control module, will monitor EGR pressures, and use that information to regulate that pressure. If any changes are made while monitoring EGR pressures, the sensor will report the new pressure values as confirmation.

EGR pressure feedback sensors use exhaust gas pressure in the EGR system to monitor how much pressure is placed on the EGR system at any given time. This can be helpful for manufacturers and engine control system software designers as a tool to understand how to finely tune the EGR system of the vehicle for changing conditions. At high engine speeds and loads, the EGR system will see higher pressures, and at low engine speeds and loads, the EGR system will see lower exhaust pressures. The engine control software will use the information from the feedback sensor to reduce or increase pressure on the EGR system for the best possible EGR system performance. This is accomplished by opening or closing the EGR valve incrementally until the engine control module is satisfied with the pressure in the EGR system. An easy way to understand the pressure sensor is to consider it a flow sensor for the EGR valve. If the EGR system is flowing at too much or too little exhaust gas, the sensor will allow the ECM notice the fault and prevent damage.

As with any EGR issue, the most common symptoms noticed when the exhaust gas recirculation pressure feedback sensor fails are rough idling, hesitation accelerating from a stop, lack of engine power, misfires, and, of course, illumination of the dreaded check engine light. Hesitation from a stop may also be accompanied by stalling or very low engine speed when slowing the vehicle down, especially from highway speeds. The vehicle may also hesitate for a short or extended time, then accelerate quickly as if the accelerator pedal were pressed to the floor.