EGR Valve

"under the plastic engine cover. It has 2 fat rubber hoses going to it."

Do you have a picture or diagram of where the EGR Pressure Sensor is? I have looked under the plastic engine cover and have not been able to locate it. I have checked the EGR Valve and it is good and I have also replaced the EGR Vacuum Solenoid and that was not the problem either. So the only thing left is the Sensor.

My code is 402. It is raining here this evening so I'm not able to work on the car but thank you for your help.

Where is the EGR Valve, and the fuel pump relay located? How hard is it to replace these items?

My 2nd. Hand 1994 Lincoln Towncar, 4.6L, has 244k miles on it, runs great, and gets good MPG! On the other hand, the local dealership service has replaced the EGR valve/tube assembly three times in only 50k miles! This is always the remedy when the Check Engine light has stayed on. Does this year/model have a history of inadequate EGR components, recall related alerts, or other known issues related to this EGR problem? Is the computer command module known to provide faulty data codes? Or, are the service techs simply replacing the EGR assembly to get the engine check light to cancel and reset? This costs me about $700. Per fix, two days without my car, and a deep disaffection for the Check Engine light.

I have replaced the EGR valve and still have a service engine light on and the pinging is still there.

How hard is it to remove and clean the EGR flow manifold elbow?

Check this out, I had a code 34 for the egr valve I replaced the egr valve and sensor, reset the timing and also released the code for the egr valve by disconnecting the main lead. My timing was off and I had it reset every time it is reset it ends up changing itself. How does this happen and why? Also what is a knock sensor and what purpose does it serve.