2002 Explorer Sport Trac
Thread Starter
|
New User
Joined: Mar 2007
Posts: 9
Likes: 0
2002 Explorer Sport Trac
When my "check engine" light came on, Auto Zone read the code as a basd "MAF" (mass air flow) sensor...I replaced it, and still it read same code..I replaced it again, used sensor cleaner that they recommended, and still it codes MAF sensor...actually, they say if it codes 2 O2 sensors at the same time, it goes back to the MAF...so, today, I replaced all O2 sensors (aftermarket), and I still have a problem...running it seems to be alright,,,I cant really tell about the gas mileage because she always did love gas....the problem is a very rough, erratic idle..like surging...so now I'm wondering...around the same time this problem started, I replaced the alternator.(again, AZ parts, new rebuilt)..the first alt I put on was bad, altho it read good...the lights flickered..the next alt fixed that problem...now I'm wondering if maybe the wrong voltage is being sent to the sensors, any or all of them...does this seem like it could be a direction to start looking, and if so, how do I check the voltage @ the MAF sensor??
thanks for any help
thanks for any help
Cargo Master
Joined: Aug 2003
Posts: 3,263
Likes: 92
From: BC Canada
Replacing parts on the recommendation of the non trained parts pusher at local Auto supply is the expensive way to fix a car.
You need to do some diagnostics. First list the codes as they appear on the scanner.
Post them here and we may be able to help...... Chrystal ball diagnostics are not reliable... Philip
You need to do some diagnostics. First list the codes as they appear on the scanner.
Post them here and we may be able to help...... Chrystal ball diagnostics are not reliable... Philip
Postmaster
Joined: May 2003
Posts: 3,310
Likes: 9
From: E.Lincoln County, NC
OMG, AZ is giving you a soaking! 
Most, I said MOST, chain store parts sellers are little more than burger flippers gone pro. 
I had a problem with my local AZ "Pro" yesterday.
From what they're telling you to replace they're probably reading P0171 & P0174, lean bank 1 & 2. The possibility is there for leaking intake gaskets but my bet is on the PCV system. Possibly a stuck PCV valve but more likely the real common problem of the pcv elbow being cracked, it cracks on the bottom where you can't see it.
Replacement comes from Ford as a complete line KCV190 Motorcraft. Some have used NAPA #9807 and cut it to fit.
In the future come here, HERE or HERE with your Sport Trac problems and stop wasting your hard earned cash!
Most, I said MOST, chain store parts sellers are little more than burger flippers gone pro. I had a problem with my local AZ "Pro" yesterday.From what they're telling you to replace they're probably reading P0171 & P0174, lean bank 1 & 2. The possibility is there for leaking intake gaskets but my bet is on the PCV system. Possibly a stuck PCV valve but more likely the real common problem of the pcv elbow being cracked, it cracks on the bottom where you can't see it.
Replacement comes from Ford as a complete line KCV190 Motorcraft. Some have used NAPA #9807 and cut it to fit.
In the future come here, HERE or HERE with your Sport Trac problems and stop wasting your hard earned cash!
Logistics Pro
Joined: Jun 2009
Posts: 4,817
Likes: 83
From: Cedar Rapids, IA
I agree with all the comments above. Don't buy parts based solely on the counter person's interpretation of the diagnostic code. Get the exact code number(s) and do some research. The code(s) should be in the form of P0123.
As for your question about alternator output being too high causing improper voltages to be seen by the sensors, just about every active sensor in your vehicle runs off of 5V which is regulated internal to the PCM. As long as the system voltage is not over 37 Vdc the reference voltage should remain a well regulated 5Vdc. You'll have a lot of other issues well before the system voltage reaches that high.
-Rod
As for your question about alternator output being too high causing improper voltages to be seen by the sensors, just about every active sensor in your vehicle runs off of 5V which is regulated internal to the PCM. As long as the system voltage is not over 37 Vdc the reference voltage should remain a well regulated 5Vdc. You'll have a lot of other issues well before the system voltage reaches that high.
-Rod
Thread
Thread Starter
Forum
Replies
Last Post
crimson080
1997 - 2006 Expedition & Navigator
2
Jul 18, 2016 09:09 AM
LastKahuna007
1997 - 2006 Expedition & Navigator
10
Sep 5, 2011 12:42 AM
AndeyHall
6.0L Power Stroke Diesel
42
Jul 6, 2011 09:32 AM
ezacarias
1997 - 2006 Expedition & Navigator
8
Jun 25, 2004 09:27 PM
