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

96,715

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 of 2 people found this helpful.
70

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

7 of 7 people found this helpful.

Your Answer

Add photo

Related Questions

Search Ford Expedition Questions

Ford Expedition Experts

#1 T_S_T
T_S_T
Reputation 1,920
#2 Larry Sturgis
Larry Sturgis
Reputation 1,360
#3 lightGear
lightGear
Reputation 1,020
View All

Related Models For Sale

Used Chevrolet Tahoe
597 Great Deals out of 32,881 listings starting at $1,500
Used Ford Explorer
904 Great Deals out of 65,303 listings starting at $799
Used Chevrolet Suburban
283 Great Deals out of 19,231 listings starting at $1,995
Used Lincoln Navigator
86 Great Deals out of 5,712 listings starting at $1,900
Used Ford F-150
2,174 Great Deals out of 195,110 listings starting at $290
Used GMC Yukon
423 Great Deals out of 20,393 listings starting at $1,495
Used Cadillac Escalade
200 Great Deals out of 10,854 listings starting at $2,500
Used Dodge Durango
281 Great Deals out of 21,230 listings starting at $1,500
Used Ford F-250 Super Duty
325 Great Deals out of 44,694 listings starting at $1,450
Used Toyota 4Runner
227 Great Deals out of 19,106 listings starting at $1,500

Used Cars For Sale

2017 Ford Expedition For Sale
34 Great Deals out of 14,543 listings starting at $26,995
2016 Ford Expedition For Sale
107 Great Deals out of 1,755 listings starting at $25,500
2015 Ford Expedition For Sale
17 Great Deals out of 593 listings starting at $19,995
2014 Ford Expedition For Sale
36 Great Deals out of 731 listings starting at $14,995

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.