Hi
Took my 1998 F150 supercab 2wd 4.6L to get the oil changed and inspected. The check engine light has been turning on and off over about the last few months. It failed inspection. Report said "P0401 Exhaust gas recirculation flow insufficient detected". Guy told me my EGR valve was bad. Took the truck to a local shop and they ran an onboard diag. and said the EGR valve was ok just clogged up and needed to be cleaned out along with probably the trottle body, est. cost $240.00. Another shop told me just go ahead and replace the EGR valve, sensor and selonoid that connects all three and that was est. at $350.00. HISTORY, about 5 yrs ago had same problem and had EGR valve cleaned and has worked ever since. Any ideas on what the best route to go would be, replace or just clean.? Also am getting ready to put a new flowmaster muffle on the truck, keeping the stock pipes, just for sound. that will not affect the insp. correct.

Thanks!!

 

The P0401 can be caused by the EGR valve itself, DPFE, or vacuum lines in the EGR system. It can also be caused by plugged up EGR ports in the throttle body. Both shops are on the right track.

 

... yet neither shop diagnosed it to the exact fault (which is easy to do) instead choosing to load up the shotgun (and the cost of the repair).

 

There should be a sticky for trouble code repair.

 

They did say it was related to, DPFE fault, so thats why the one shop recommended cleaning things up. What would be the best way to diagnose the EXCAT problem?