Last reported case: 6 years ago
Based on 9 owner reports, 9 from forums)
What is P0171?
P0171 indicates your engine's Bank 1 is running with too much air and not enough fuel, which is called a 'lean' condition. This is a medium-severity powertrain issue that can reduce fuel economy and performance, and it's commonly triggered by vacuum leaks or faulty sensors. Based on 551 reports, repairs for this code average $4596, with Ford Mustangs and F-150s being among the most frequently affected vehicles.
Common Causes:
- Vacuum leaks in intake hoses or gaskets (reported in numerous discussion clusters)
- Faulty mass airflow (MAF) or oxygen (O2) sensors
- Clogged or failing fuel injectors
- Fuel delivery issues like a weak fuel pump or clogged filter
Symptoms:
- Check Engine Light is illuminated
- Reduced engine power or hesitation during acceleration
- Poor fuel economy
- Rough idle or engine misfires
šP0171 on 2020 FORD Expedition
This page focuses specifically on P0171 issues reported by 2020 FORD Expedition owners. The experiences and fixes below are from real owners of this exact vehicle.
Symptoms Reported by 2020 FORD Expedition Owners:
Parts Often Involved:
What Owners Say
Real experiences from 2020 FORD Expedition owners
āWith the engine off, it pretty much just pulled out and went back in real easy. Then I just followed it with my hand the best I could ( with the motor now running so be careful!!) until I got back to the firewall, and it actually comes up from underneath the rear of the intake. .āView original
āOr you might be able to just replace the elbow itself. Either way, make sure if you do have the leak, to make sure you have the replacement part handy before you take off the old one, because it will crumble in your fingers!!āView original
āAny advice would be greatly appreciated. Iām a veteran single income family of 4 and Iām pretty tired of paying $1,000ās to my mechanic (even though I love and trust him)āView original
āSo I replaced both, Light stayed on. So I bought a scan tool. https://www.boschdiagnostics.com/diy/products/bosch-obd-1200 and went home to do some testing.āView original
āAfter some searching, I found a possible cause would be VVT stuck, or the Phaser is going out. I pulled everything on bank to side and removed valve cover, and phaser isn't bent or stuck, so I put it all back together (unplugged battery for this) and after 4 engine run cycles I came up with these codes.āView original
āYou have been a member for over 2 years now with a total of 44 posts or replies to posts. I went back and read most of them and I could not find any reference to your "prolonged unexplained problem" that "has been going on for about a year with the codes popping up which is P0171 and P0174" Just maybe had you posted about that problem and the codes you would have solved the problem months ago.āView original
āI idle at a steady 600rpms..no hesitation. When in gear, and accelerating, at around 1200rpms I get a whistle that my passengers -and myself- think sounds like turbo kicking in..(I dont have turbo)... when I release the accelerator it goes away...āView original
āSeems to me if it's only bank 1 and not both, it's probably not fuel filter or fpr related correct? I'm thinking I should be looking for a bad injector.āView original
ā"turbo" sounding whistle when I accelerate w/ P0171+0174 I have codes P0171 and P0174. 02, 4.6, XLT I replaced the PCV elbow behind the TB and the PCV vlv.āView original
āP0171, P0174 after heavy rain Not sure if rain was just a coincidence or not but the other day the rain was very heavy, truck sat for 2 days then this morning about midway into my 40 Mile commute the CEL came on.āView original
These are real experiences shared by 2020 FORD Expedition owners on automotive forums and communities. Results may vary based on vehicle condition and repair quality.
About This Data
This page aggregates 9 discussions about P0171 from 2020 FORD Expedition owners across automotive communities.
Success rate (33%) is calculated from posts where owners confirmed whether their fix resolved the issue.
Last updated: 1/4/2020