Tip#22: Obd1 332 DPFE sensor code for 94 Ford Explorers

When checking for check engine light and code 332 appears, the normal procedure to repair this code is check and repair if necessary the egr valve, the evr solenoid or clean the passages between the egr and your intake ports. However, after doing all of these, the obd1 code returns because a lot of guys forget the dpfe sensor and most of the time, this is the culprit!

Symptoms:

Code 332 displayed after scanning the codes
Engine stalls when vacuum is manually applied to the egr valve

Basic Concept:

On most OBD1 Ford 92-94 egr system, the egr valve has a dpfe sensor sitting on top of the egr valve. What is does is measure the pressure going between the intake manifold and exhaust manifold. The difference between the 2 pressures is sent as an output signal to the ecm. As a result, the ecm can calculate the proper vacuum flow thru the evr solenoid and egr valve. If this dpfe sensor is defective, the vacuum flow might not be enough causing an issuficient flow resulting in obd1 code 332.

Testing the dpfe sensor is simple. Just apply 8-9 inches of vacuum using a hand held vacuum pump to the intake port opening. Then measure the voltage to the center wire of the 3 terminal plugs in of the sensor. You will notice the reading is about 4 volts or more. As soon as you release the vacuum, it should go down to 1.5 volts within 3 seconds. If it is not doing this, replace the sensor. Double check also the hoses going to this sensor before replacing it.