I know this is off explorer topics, but any help would be appreciated, it's about to get the best of me! Thanks for all of the help on both of my explorers , and my nephews also.
2001 SuperCrew F150 V8 4.6L
140K miles (highway)
Problem: P0401 code (insufficient EGR flow) *Main problem!* Light blue smoke on startup (started 137K) probably valve seals. Uses a little oil now. About 1qt in last 3K miles.
History: 100K Replaced spark plugs 125K (had P0401 code). Replaced DPFE and EGR valve (EGR valve was still good). Cleaned EGR pipe. Cleaned Throttle body which was completely clogged on the EGR ports. Reset code and it worked fine until now! 137K IAC valve went crazy and was replaced 140K P0401 code came back!
Does anyone have any idea what I should try next to remove the P0401 (insufficient EGR flow) code? I checked the following things this weekend:
- All hoses seem fine and have vacuum.
- DPFE hoses are clean and both have air flow.
- EGR valve will hold vacuum and the engine runs rough when it is engaged with vacuum at idle. (I think that is one of the tests)
- The hose to the EGR has pulse vacuum at idle and the EGR solenoid valve has vacuum to it also.
- I removed/inspected the throttle body again anyway and it appeared "clean", no ports clogged.
- Reinstalled everything and code came back after about 75miles.
What am I overlooking or have not tried? Any help would be appreciated!
Thank you in advance for your help.
Richard Grimes