I am new to this sight. I have a 99 F-150 with a service engine light on. The code says restricted airflow to EGR valve. I purchased an EGR valve from Auto Zone and replaced the old one. I disconnected the battery to reset the code and the light went off. The next day the light came back on. I checked the code P041 (I think) this time I deleted the code with the handheld computer. Today the service engine light is on again. Any suggestions?

 

P0401 is probably the most common code on these trucks discussed on this forum.

Please avail yourself of the SEARCH tool.

The dummies at AutoZone strike again! Yet another unneeded EGR valve sold.

Steve

 

I suffered through the same problem with code P0401. I too changed the ERG Valve and the PDFE switch and it did not fix it. Same as you the light came back on in a few miles, but I finally fixed my 98 4.6L F150 with 112,000 miles by cleaning the ERG ports. The ports I'm speaking of can only be accessed my removing the throttle body elbow off the top of the intake manifold. It's an elbow that connects most of the vacuum lines including the ERG Valve. I got a lot of carbon out of their using a drill bit by HAND and that fixed it. There is a simple test to tell you if the ports are clear.

Remove the vacuum line from the ERG Valve and cap the hose. Start the engine and let it idle. Then apply vacuum (outside source) to the ERG Valve. The engine will stumble or stall if the ports are clear. If the engine continues to idle without change the ports are blocked and need to be cleaned. I cleaned mine in about an hour it's not that big of a deal on the 4.6L

Good Luck

 

Thankyou for your response I will definitely try your suggestions. I won't be so quick to jump on the obvious solution next time.