P0402moderate severityPowertrain
EGR Flow Excessive Detected
on 2001 Mazda 626 2.0L I4 · FWD
What this code means
The EGR system is flowing too much exhaust gas.
Symptoms
- Check Engine Light
- Rough idle
- Stalling
- Surging
- Poor acceleration
Common causes
- EGR valve stuck open
- Faulty EGR solenoid
- Vacuum leak to EGR valve
- Faulty DPFE sensor reading low
Diagnostic steps
- Check EGR valve for stuck-open condition
- Test EGR solenoid
- Check vacuum lines
- Test DPFE/position sensor
Repair notes
Replace EGR valve if stuck open. Repair vacuum lines.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1