I have a 1998 Ford Explorer and I can't get the P0171 or P0174 trouble codes out I've replaced all 4 o2 sensors mass airflow sensor DPFE sensor plugs Sea Foam throtle position sensor checked for vacume leaks cleaned egr valve just about everything I could think of HELP!!!!

You missed two spots.

EGR air passage tube

and

EGR base gasket

The air passage tube get clogged with carbon just like the base of the EGR valve.

It's ten time worst!!!

Get a full bottle of SeaFoam,WD-40 and a snake/wire to clear out this passage.

A home vacuum clean will help speed up the job.

DO NOT forget to get a new EGR base gasket.


Good luck

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Actron CP9410 PocketScan Plus Code Reader aster_cloud_id = '2423281'; aster_cloud_format = '800x200'; document.write(unescape("%3Cscript src='http://web.asterpix.com/media/js/searchlight.js' type='text/javascript'%3E%3C/script%3E")); FAQ: How do I reset the "Check Engine" Light? After you've properly diagnosed and fixed the problem that triggered the OBD trouble code, you can reset or clear the Check Engine / Service Engine Soon light by one of two methods.
Note: The code (i.e. CEL / SES light) will usually go away after a certain number of driving cycles, perhaps a few days. You can choose to wait it out or follow one of these methods.
The cheap, easy, free method Simply disconnect your battery, turn on the headlight switch
for about five to ten minutes, and re-connect the battery. This is pretty simple, but will likely result in you losing your radio presets and perhaps some other small things like that.
Using a scan tool Most if not all scan tools
have an option to clear or reset codes without the use of any tools or touching the battery. Consult your tool's manual for information on how to do it with your particular model.