Mechanics

EGR

Ford Taurus

1999 Ford Taurus SE, 163,000, V6 24 valve DOHC

A few weeks ago my " service engine" light came on. The code was " insufficient airflow to the EGR". So I replaced the EGR valve & had the carbon cleaned out of the intake. My service engine light came back on. So I replaced the other two parts that go to the EGR system in Ford's, which were the EGR Vacuum Solenoid (the switch), and the EGR Valve Pressure Sensor (the control unit) this past weekend. However, my " service engine" light has again come back on giving the exact same error. And I've tried having it reset multiple times already & just driving it waiting for it to go off all to no avail. Do you know what is going on? Also, I live just outside of Atlanta, GA & thus I have to pass an emissions inspection in order to renew my plates. Which I have been unable to do because of this code. Is there any way that I can bypass the EGR system & at least get my car to pass the emissions test until I can figure out what's going on? As I've replaced everything that it should be effecting, I'm thinking maybe my computer is just being temperamental.

Please help
Avatar
Srholmes
July 9, 2007.



Here's a dirty little secret: The codes that you get don't always tell you the components that cause the problem, only the symptoms.
Think of it this way: You could go to the doctor with chest pains, and you're thinking you are having a heart attack. Then later you found that you just had a bad case of gas.

The computer is complaining about the EGR system. Let's look at what feeds the EGR system, and we should be able to find the problem.

The EGR valve simply takes a portion of the exhaust gases, which still contain some combustible fuel, and feeds it back into the intake manifold. It is only supposed to operate when you are not idling, and the throttle is at least partially open (acceleratiing).

In other words, the problem could just as easily be in the intake manifold, such as a vacuum leak.

I make it a habit to not even read the computer until I check for vacuum leaks.

I had a similar problem, except that I was also idling rough and stalling. I got all kinds of codes, such as EGR, throttle position sensor, idle air control valve, etc. I changed one part, and I'd get a code for a different part. No matter how many parts I changed, I'd get a code.
It turns out that there is a boot-shaped PCV hose that is hidden from view. You can't see it until you remove the upper plenum. It was badly worn, and once I replaced it (at a cost of $15.00), the engine ran perfectly.
Then, I went back and put some of the " bad" parts back. The car still ran perfectly. So I learned an expensive lesson.

Tiny
Blm
Sep 26, 2007.