Hello!!! I have a 2002 Mustang, 3.8L, Auto, 85,500 miles. The other day I ran the Air for a while, and got the dreaded "SERVICE ENGINE SOON" warning light. I went down to Auto Zone and had it tested, the DTCS was P0401 (EGR Flow Insufficient). I replaced the EGR Valve, and cleared the computer (disconnecting the ( - )pole of the battery, and pumping the brakes a few times). leaving off for 30 mins. Took it for a ride, and it went on again after about 10 miles. I went back to Auto Zone and had it tested got the P0401 again!! Then I replaced the EGR Sensor, cleared the computer, and it went away. I drove it for about 125 miles, I used the " TRAC OFF" option, and the warning light came on again!!! Since then I have cleared the computer, and it runs clean. I just want to know what is happening here?
Did I have to replace the 2 EGR parts, or is there something else wrong?? Something maybe about the voltage?? I don't know???? Anyone have a clue??? I have the feeling if I use the air, or TRAC OFF, that it is going to come back. Thanks, BRM
Did I have to replace the 2 EGR parts, or is there something else wrong?? Something maybe about the voltage?? I don't know???? Anyone have a clue??? I have the feeling if I use the air, or TRAC OFF, that it is going to come back. Thanks, BRM