How do you figure out why the check engine light keeps coming on?
20

Asked by GuruNQF53 Jun 19, 2022 at 04:00 PM about the 2004 Ford Expedition

Question type: Maintenance & Repair

I have a used 2004 Expedition, the check engine light was on, change out
the spark plugs (when doing so there were 5 different types of plugs!), and
changed the ignitions coils (there were 4 different types of these!) Engine
light was still on
so far I have changed
Spark plugs
Ignition coils
Mass airflow
PCV valve
Fuel Filter
used gas additive
codes were erased, check engine light went off.
About a week after replacing the mass airflow filter the check engine light
came back on.  I thought now I will know what the real problem is, went to
auto zone run the code reader.  The only thing that came up was the mass
airflow filter!
With a brand new mass air flow filter, one would think that was not the
problem.

6 Answers
2,920

VRoom12345 answered 2 years ago

Most times a Mass air flow code is not the unit itself that is the issue and no need to replace it. What is the 4 digit code?

1 people found this helpful.
Mark helpful
157,515

James answered 2 years ago

What code do you have? It could be the wiring going to the MAF and not the sensor itself. Hope that helps! Jim

Mark helpful
157,515

James answered 2 years ago

P0171 is a lean air to fuel mixture on the side of the engine where cylinder number one is. C1175 is the left rear wheel speed sensor circuit failure. The circuit is either open or shorted. So neither code is for the MAF. The P0171 could be a vacuum leak, intake manifold leak, exhaust system leak, cracked exhaust manifold, or bad oxygen sensor. You need to concentrate your efforts on the side of the engine where the number one cylinder is. The C1175 code is pretty self explanatory. Hope that helps! Jim

Mark helpful

Your Answer:

Related Questions

Expedition

Looking for a Used Expedition in your area?

CarGurus has 810 nationwide Expedition listings starting at $7,888.

Postal Code:

Shortcuts

Search Ford Expedition Questions

CarGurus Experts

  • #1
    Larry Sturgis
    Reputation
    5,300
  • #2
    T_S_T
    Reputation
    4,560
  • #3
    Gene Arnett
    Reputation
    2,730
View All

Find great deals from top-rated dealers

Search

Related Models For Sale

Used Chevrolet Tahoe
19 Great Deals out of 716 listings starting at $5,995
Used Chevrolet Suburban
4 Great Deals out of 406 listings starting at $12,000
Used Ford Explorer
83 Great Deals out of 1,991 listings starting at $2,999
Used Lincoln Navigator
5 Great Deals out of 196 listings starting at $9,869
Used GMC Yukon
19 Great Deals out of 741 listings starting at $5,998
Used Ford F-150
289 Great Deals out of 15,384 listings starting at $1,712
Used GMC Yukon XL
13 Great Deals out of 541 listings starting at $12,950
Used Toyota Sequoia
4 Great Deals out of 72 listings starting at $16,489
Used Cadillac Escalade
14 Great Deals out of 396 listings starting at $6,995
Used Toyota 4Runner
14 Great Deals out of 328 listings starting at $9,900
Used Ford F-250 Super Duty
29 Great Deals out of 1,154 listings starting at $8,995
Used Nissan Armada
16 Great Deals out of 181 listings starting at $6,999
Used Chevrolet Silverado 1500
211 Great Deals out of 5,943 listings starting at $3,995
Used Ford Excursion
2 listings

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. Content will be removed if CarGurus becomes aware that it violates our policies.