Hi all,I have a 2001 Explorer Sport with a 6cyl/4.0L engine in it, i have been told it is what is called 2nd generation engine, because it replaced the original engine that was in these models. Anyways, my check engine light came on and i have recieved these codes, P0401, P0171, P0174. Any ideas on where and what i should be looking at to help solve them. Any and all help is greatly appreciated. Thank you in advance.

 

I'd start by replacing the DPFE. This is a common code generator for these codes.





P0401
Exhaust Gas Recirculation Flow Insufficient Detected

P0171
System tooLean (Bank 1)

P0174
System too Lean (Bank 2)

 

Ive been looking around online at the dpfe thingy, what is the difference between the one for $26.00 form autozone, and the one for about $72.00 from O'reilly's? That seems like a wide range in price for that thing. Is it worth it to spend the extra money on that part. Any ideas and help is appreciated. Thank you

 

Should be no difference except for the MFG of the unit and how much they want to charge you for it. I show Autozone listing the one for your vehicle for $48. You could cruise EBAY and pick one up for about $20-25. I just got one for my 2000 Taurus for $25 including shipping.

 

Well i replaced the dpfe sensor, and erased the codes out of the system, i went driving for a while. The CEL light came back on, but this time it was just for 0171 and 0174. The 0401 was gone. Any ideas of what to look at?!

 

Look for a vacuum leak somewhere

 

Yea, i found some older posts and some other sites that said for the 2 codes i have now to do 1 of several things. Look at the MAF sensor and possibly clean it if need be. Check the O2 sensor, one of those may be bad, and the vacuum leak. So i guess i will hunt around for those problems the next few days.

 

are there any particular areas to look at for the vacuum leak?!?!

 

I am getting the same codes (Lean) I was told to change the lower intake manifold gaskets. Have you found your problem?