Check engine light keeps coming on (p0401).

Asked by Feb 19, 2014 at 10:04 PM about the 1999 Ford Expedition 4 Dr XLT 4WD SUV

Question type: Maintenance & Repair

Replaced the engine in my 1999 Ford Expedition.   Check Engine light keeps coming on.  
Replaced  the EGR valve, sensor and solenoid...car runs fine...but the check engine light
keeps coming on with the same P0401 code??????

2 Answers

55

check your gas cap if not tightened properly, it may cause check engine light to stay on. or if your gas cap is not that of your vehicle, it will also cause light to engage . you may have to have the comp reset.

2 of 2 people found this helpful.

I also replaced modulator, air intake boot, pcv and grommet and some vacuum lights. I just replaced the gas cap and saw that my gas cap was missing a large plastic cylinder piece from the inside. Cleared code p0401 from my 1998 toyota camry. And hasn't returned so far. But it's only been the morning so far. We will see.

Your Answer

Ford Expedition Experts

  • #1
    T_S_T
    Reputation
    2,290
  • #2
    Larry Sturgis
    Reputation
    1,570
  • #3
    lightGear
    Reputation
    1,060
View All

Related Models For Sale

Used Chevrolet Tahoe
813 Great Deals out of 40,153 listings starting at $1,900
Used Ford Explorer
1,085 Great Deals out of 67,941 listings starting at $1,200
Used Chevrolet Suburban
509 Great Deals out of 23,421 listings starting at $2,700
Used Lincoln Navigator
95 Great Deals out of 3,627 listings starting at $2,900
Used Ford F-150
3,014 Great Deals out of 230,516 listings starting at $1,300
Used GMC Yukon
500 Great Deals out of 19,417 listings starting at $1,995
Used GMC Yukon XL
297 Great Deals out of 13,430 listings starting at $1,750
Used Cadillac Escalade
279 Great Deals out of 12,215 listings starting at $2,995
Used Dodge Durango
267 Great Deals out of 24,908 listings starting at $1,500
Used Ford Excursion
12 Great Deals out of 809 listings starting at $3,900
Used Ford F-250 Super Duty
436 Great Deals out of 47,677 listings starting at $2,400

Used Cars For Sale

2018 Ford Expedition For Sale
5,925 listings starting at $45,499
2017 Ford Expedition For Sale
143 Great Deals out of 4,934 listings starting at $23,500
2016 Ford Expedition For Sale
77 Great Deals out of 1,456 listings starting at $18,991
2015 Ford Expedition For Sale
29 Great Deals out of 878 listings starting at $18,500
2014 Ford Expedition For Sale
41 Great Deals out of 942 listings starting at $12,990

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.