Code 31 on 1988 f150

On the 5.4 aand 4.6 trucks the egr port on the upper intake manifold clogs up with carbon. The other issue is the EGR DPFE ( delta pressure feedback egr sensor) will get condensation inside and through a code. The cheapest thing would be to pull the upper intake elbow and clean it. DO NOT CHANGE THE EGR SENSOR, try cleaning the upper intake first.

sounds like either a vacuum leak (check the bottom of the "tomatoe juice can" for starters) or a bad or plugged egr valve or egr solenoid.
check engine lite refers to emissions probs only...most likely egr or vac leak. Had the same prob on my 95 5.0 f150...needed new can and egr valve.

http://www.obd-codes.com/p0147

if car has 3100 remove egr valve clean port hole fills with carbonit run pice of coat hange throught it er move air tube on throttle you will see a hole on right side that need to be cleand outsome good carb cleaner wellhelp to hole might behind plate been long time since i did one

I have a 2005 6.0 liter powerstroke f-250 with P0404 and P0405, I have tried cleaning the egr valve and reset the code worked fine for a little while then the codes came back. Any Idea what's going on?

should be a p0401 could be dpfe sensor,hose off of the sensor, clogged pipe from sensor to manifold,clogged egr passages,bad egr valve i see these daily most time not same causes but generally one of these also bad egr vacuum solenoid

Everyone says to test out your DPFE sensor. This controls the flow of the egr. When the codes pull up, everyone thinks its the egr, but really its this little guy.
Take it by a shop and see if they can mess with the bugger. They usually run about $50+.

First make sure all lines are connected to EGR , if not ,connect them if they are? Then remove EGR value and clean and reconnect.

There are 4 egr related items on your truck. A egr valve, a egr solenoid, a egr vaccum manifold switch, and a egr relay

It is very possiable that you may be getting a false code that will reocure till egr problems are repaired. The ecu may be trying to compensate for egr problems causing it to send the 607 code