2001 4.2 "bank one running lean"
11-04-2009, 05:42 PM
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2001 4.2 "bank one running lean"
Check engine light came on a few days ago. Had it scanned, one code: bank one running lean...cant remember code number.
Went through this same problem back in February, only it was both banks.
One O2 sensor on the down stream was all funked up...replaced all 4.
Light came on a few weeks later...found vacuum leak from broken gromet where the pcv line plugs into throttle body. Truck has the black plastic plentium.
No problems until this week....I read in the forums that there is an elbow on the back of the plentium...thought i would try and find it to see if it is cracked....
Can you see it or do you have to feel for it....any other ideas? EGR??
Parts Replaced in March 2009
4 O2 Sensors
Heated PCV line
Molded vacuum line that runs between air intake hose and valve cover
Plugs (motorcraft double platnium)
Wires
Coil Pack
Fuel Filter
Intake and Throttle Body cleaned
MAS cleaned
Many Thanks in advance....
Mechman
Went through this same problem back in February, only it was both banks.
One O2 sensor on the down stream was all funked up...replaced all 4.
Light came on a few weeks later...found vacuum leak from broken gromet where the pcv line plugs into throttle body. Truck has the black plastic plentium.
No problems until this week....I read in the forums that there is an elbow on the back of the plentium...thought i would try and find it to see if it is cracked....
Can you see it or do you have to feel for it....any other ideas? EGR??
Parts Replaced in March 2009
4 O2 Sensors
Heated PCV line
Molded vacuum line that runs between air intake hose and valve cover
Plugs (motorcraft double platnium)
Wires
Coil Pack
Fuel Filter
Intake and Throttle Body cleaned
MAS cleaned
Many Thanks in advance....
Mechman
Last edited by mechman072; 11-04-2009 at 05:44 PM. Reason: can't spell
11-05-2009, 10:07 AM
#2
Senior Member
There are several different write ups about the PO171. Suggest using the search button, "PO171" select posts and hit go.
Personnally complying with the TSB about the isolator bolts cured mine for 18 months. Yes it came back, actually PO174. This was corrected automatically when I replaced the failing vaccuum booster. It was a $300.00 repair, so I don't recommend it in your case.
The TSB covered these isolator bolts and grommets, originally they were black and changed to green grommets for better sealing.
Aside for the large vaccuum booster line, the only other vac lines that I remember comming from the plenium chamber go to the EGR solenoid.
Go to the dealership and ask about the TSB and the isolator bolts, am confident this will fix your problem. I doubt if the local parts houses even carry the bolts with grommets let alone the improved green material type.
Personnally complying with the TSB about the isolator bolts cured mine for 18 months. Yes it came back, actually PO174. This was corrected automatically when I replaced the failing vaccuum booster. It was a $300.00 repair, so I don't recommend it in your case.
The TSB covered these isolator bolts and grommets, originally they were black and changed to green grommets for better sealing.
Aside for the large vaccuum booster line, the only other vac lines that I remember comming from the plenium chamber go to the EGR solenoid.
Go to the dealership and ask about the TSB and the isolator bolts, am confident this will fix your problem. I doubt if the local parts houses even carry the bolts with grommets let alone the improved green material type.