my expedition is giving me codes P0171 and P0174 which means system too lean on bank1 and bank 2

Asked by Feb 04, 2015 at 09:34 PM about the 1998 Ford Expedition 4 Dr XLT SUV

Question type: Maintenance & Repair

I actually had 3 codes when i took to shop they replaced intake gaskets done coolant
flush and replaced # 2 sparkplug cause it was cracked do from leak of intake gasket and
that was the 3rd code i mentioned P0302 and it fixed the feel of it driving well today i
turned my defrost/heat on and smelt antifreeze and my front heat blows cold air but rear
heat works wonderful please any suggestions

2 Answers

83,395

First replace the fuel filter, then run a fuel system pressure test, if the pressure tests good then clear the codes and verify they cleared, then road test, if the check engine light comes back on with the same codes you may have partially plugged injectors or you still have an internal vacuum leak. Coolant smell from the heater is almost always a leaking heater core, on this rig it is not cheap to replace, the part price is not bad but the labor is the killer.

2 out of 2 people think this is helpful.
60

PO171 And PO174 means it's running lean. This means your manifold air pressure sensor is saying X amount of air entering motor yet your O2 sensor is saying XY amount of air is exiting engine. The computer reads this as extra air is getting in somewhere. This is usually a vacuum leak from your PCV vacuum lines. Start your engine, let it idle. Spray starting fluid around your PCV valve and all vacuum lines connected to it. You should hear you idle pick up. Then trace those lines with your finger and you will find a hole that rotted through. go to the following links for more help and videos. https://www.facebook.com/martin.kamenar.92 and https://www.youtube.com/watch?v=YaynnTca3tw&feature=youtu.be

6 out of 6 people think this is helpful.

Your Answer

Add photo

Related Questions

  • 01 expy 5.4 p0171 p0301 runs rough 15 answers

    Last week our 2001 expedition started running rough during a rain storm. We took it home and parked it for a couple days to let it dry out. Still ran rough after drying but now had a check engine l...

    2001 Ford Expedition XLT 4WD

    -

    Maintenance & Repair

  • 2001 ford expedition 125k miles P0171 and p0174 9 answers

    Can't find the problem •I replace the pcv hose •Clean the mass air flow •Replace the fuel filter (old one wasn't bad) •Sprayed the whole car with carb cleanner and nothing •Replace the throttle...

    2001 Ford Expedition

    -

    Maintenance & Repair

  • P0171 P0420 P0430 - Little enging power - 03 Expedition 1 answer

    The 2003 Ford Expedition 4.6L 2WD idles fine when cold at about 1000 RPM, but upon warming the idle drops to 700 RPM. When the throttle is past 1/3 the power flattens out. The Freeze frame data from...

    2003 Ford Expedition

    -

    Maintenance & Repair

  • 98 expedition bank and shut off problem. 7 answers

    my 98 expedition keeps blowing bank #6 plug n spark plug, after replacing all 4 driver side coils and plugs.at firs ok for the first day. now randomelly shuts off when turning or taking off after a ...

    1998 Ford Expedition 4 Dr Eddie Bauer SUV

    -

    Maintenance & Repair

  • p0174 system too lean bank 2 + flashing engine light 4 answers

    I recently got the P0174 code and the engine light also flashes some of the time (misfire?). I have a Ford Taurus 1998. The car runs fine except when I go up a hill it lacks power and cannot go pas...

    1998 Ford Taurus SE

    -

    Maintenance & Repair

Search Ford Expedition Questions

UK Questions

Are you a UK consumer? CarGurus now has a discussion forum in the UK.

Ford Expedition Experts

#1 T_S_T
T_S_T
Reputation 1,680
#2 oldtimer37
oldtimer37
Reputation 1,140
#3 lightGear
lightGear
Reputation 1,010
View All

Related Models For Sale

Used Chevrolet Tahoe
831 Great Deals out of 28,003 listings starting at $1,700
Used Ford Explorer
1,093 Great Deals out of 72,155 listings starting at $1,000
Used Chevrolet Suburban
558 Great Deals out of 19,205 listings starting at $1,964
Used Lincoln Navigator
129 Great Deals out of 5,953 listings starting at $1,299
Used Ford F-150
3,105 Great Deals out of 209,134 listings starting at $1,200
Used GMC Yukon
559 Great Deals out of 17,232 listings starting at $1,875
Used Cadillac Escalade
295 Great Deals out of 10,301 listings starting at $1,900
Used Dodge Durango
373 Great Deals out of 23,259 listings starting at $1,500
Used Jeep Grand Cherokee
912 Great Deals out of 66,711 listings starting at $1,500
Used Ford F-250 Super Duty
467 Great Deals out of 43,492 listings starting at $1,900
Used Chevrolet Silverado 1500
2,580 Great Deals out of 152,650 listings starting at $1,500

Used Cars For Sale

2017 Ford Expedition For Sale
5 Great Deals out of 12,282 listings starting at $23,087
2016 Ford Expedition For Sale
66 Great Deals out of 1,735 listings starting at $27,401
2015 Ford Expedition For Sale
82 Great Deals out of 1,515 listings starting at $22,811
2014 Ford Expedition For Sale
29 Great Deals out of 816 listings starting at $16,995
2013 Ford Expedition For Sale
60 Great Deals out of 1,010 listings starting at $16,944