thanks guys!! I love this place.

I just spend a couple days with this
 

I just spent a couple of days figuring my P0401 code out. I learned more than I wanted to know about this system. I have taken some photos and put together a slide show about how I troubleshot my system, this may help others. I am not a certified Auto Mechanic, nor do I work for Ford, etc. If I made a mistake, please let me know and I will correct.




http://home.coastalnow.net/~a64armt...0401/Slide1.JPG

http://home.coastalnow.net/~a64armt...0401/Slide2.JPG

http://home.coastalnow.net/~a64armt...0401/Slide3.JPG

http://home.coastalnow.net/~a64armt...0401/Slide4.JPG

http://home.coastalnow.net/~a64armt...0401/Slide5.JPG

On a 97 Ford Ranger..Can someone tell me for sure where the EGR valve is?..thanks

You can thank the EPA for EGR. Ford uses the DPFE to monitor the EGR valve. It reports to the ECM about the "flow" through the EGR. If the EGR ports are clogged with tar and soot(no EGR flow) the EGR could be OK, but the DPFE is still going to tell the ECM it is bad. You need to check the ports to be sure they are clean. If they're clean the EGR or DPFE could be faulty. The DPFE could erroneously report a fault(false postive) or the EGR could actually be defective. The other thing is the vacuum solenoid and vacuum line from it to the EGR value. You can eliminate all these problems if you're out of warranty by bypassing the EGR. Disconnect the tube from the bung on the exh man. Block off the bung. Now the exhaust goes out the exhaust and when the ECM commands the EGR to flow it pulls in fresh air. You can even stuff some K&N filter material up into the tube as a filter if you want. You will never get P0401 again.