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Check engine light on?

Tiny
NOLAFORD
  • MEMBER
  • 1999 FORD F-150
  • 6 CYL
  • 2WD
  • MANUAL
  • 126,000 MILES
I was driving my truck the other day and the truck was sluggish and acted like it was missing when the truck got up to about 15mph (2nd gear). At a stop sign I noticed the mileage reading was blank, someone told me one time that you could restart the computer if you while driving if you shifted into neutral and turned the vehicle off and restarted. Even though that is the dangerous way to do it and considering that I was in a closed parking lot, I did it and when the truck restarted the mileage reading was displayed and the truck was running better. I have had the check engine light on about a month; a mechanic read the code and said it was an O2 sensor and that it was a big deal. I wasn't sure if two problems were related, but I figured it may have been relevant.
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Saturday, December 12th, 2009 AT 8:34 PM

24 Replies

Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Read this guide to get the codes

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

This video will help you clear the codes

https://youtu.be/ahK_eucFi-k

Please let us know what happens. Please run down this guide and report back.
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Saturday, December 12th, 2009 AT 8:55 PM
Tiny
K_SANDERS
  • MEMBER
  • 1 POST
  • 1999 FORD F-150
  • V8
  • 2WD
  • AUTOMATIC
  • 233,235 MILES
Noticed lately my truck has been "knocking" the last 3 days. Now the "check engine soon" light just came on and engine seems to be knocking a little more. What could it be? Also, I need to make a 66 mile round trip and will it be ok to drive it this long before getting it looked at? Thanks.
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Wednesday, September 9th, 2020 AT 6:24 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,885 POSTS
Before driving it, I would recommend having the computer scanned to identify what is causing the knock. My concern is most knocks deal with bearing problems. If that is the case, you will do more damage. Is the oil full? Also, most nationally recognized parts stores will scan the computer for free. Have that done and let me know what you find.

Joe
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Wednesday, September 9th, 2020 AT 6:24 PM (Merged)
Tiny
REDNECKCHICK8186
  • MEMBER
  • 1 POST
  • 1999 FORD F-150
Other Category problem
1999 Ford F150 V6 Two Wheel Drive Automatic 149437 miles

The place where im getting my truck inspected said that I cant get it inspected because my SES light dosnt come on when you go to start up the truck. I cant find a solution to this problem anywhere and I have never heard of this problem all my life. And ive already checked the bulb and its still good. Can you help me please?
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Wednesday, September 9th, 2020 AT 6:24 PM (Merged)
Tiny
FLEXY5
  • MECHANIC
  • 512 POSTS
By SES Are you refering to the air bag light. Ford never put an SES light on their dash. It is either an yellow emblem of a person sitting, or it simply says air bag. But either of these should come on for about 3-5 seconds when the key is turned on. If not, check for blown fuses. Please post your findings as this will help others in the future.
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Wednesday, September 9th, 2020 AT 6:24 PM (Merged)
Tiny
RUFUSPORTER
  • MEMBER
  • 14 POSTS
  • 1999 FORD F-150
  • V8
  • 2WD
  • AUTOMATIC
  • 180,000 MILES
I tryed every thing and my check engine light just keeps coming on.I have a 1999 ford F-150 with a OBII code P0401. I changed the EGR and the DPFE (Differsential Pressure Feedback EGR Sensor.)Erased the engine light drove almost 50 miles to reset the trucks brain just to have the engine light come back on with the same code.
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Wednesday, September 9th, 2020 AT 6:25 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Use a vacuum pump and pull the EGR valve open while monitoring engine RPM's, There should be a noticeable difference in RPM's with the EGR open
Clean out the EGR valve and/or tubing to remove deposits
Check the voltage at the DPFE, compare to specified values (refer to a repair manual for your specific model)
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Wednesday, September 9th, 2020 AT 6:25 PM (Merged)
Tiny
CHUCK46
  • MEMBER
  • 1 POST
  • 1999 FORD F-150
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 250,000 MILES
My ford f-150 4.2 sputters and misfires when I step on the gas? What may be the problem?
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Wednesday, September 9th, 2020 AT 6:25 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,885 POSTS
If the vehicle hasn't been tuned for some time, you may want to check wires and plugs. Also, check for vacuum leaks. Make sure fuel pressure is within specifications. There is a how to check fuel pressure on our home page under the DIY section. Since it is missing when you put a load in it, I feel it is ignition related, but can't be sure until fuel pressure is checked.
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+1
Wednesday, September 9th, 2020 AT 6:25 PM (Merged)
Tiny
GILDEE
  • MEMBER
  • 1 POST
  • 1999 FORD F-150
  • V8
  • 4WD
  • AUTOMATIC
  • 100,000 MILES
Well this has been happening for the past month or so intermittently. And until recently the check engine light had not come on. It only starts to shake when in drive idling, or when in drive and accelerating. Shifting into neutral or park eliminates the shaking and the rpms back to normal. I had a similar problem a year or two ago and had the fuel filter replaced, which fixed the problem. Just wondering what ideas are for this and if it might be the fuel filter again, or possibly something else.
Thanks!
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Wednesday, September 9th, 2020 AT 6:25 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,885 POSTS
It could be a fuel filter again or the pump. You should check fuel pump pressure to see if there is a problem there. Here is a how to:

https://www.2carpros.com/how_to/how_to_check_fuel_pressure.htm

HOWEVER: Since the check engine light has come on, I recommend having the computer scanned. It should identify where the miss is coming from. If it is a "random misfire" then check the fuel pressure. If it is a specific cylender, check the spark plug, coil pack...

If the vehicle hasn't been tuned up in a long time, that may be a good idea.

Let me know if you have other questions.
Joe
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Wednesday, September 9th, 2020 AT 6:25 PM (Merged)
Tiny
CURREN93
  • MEMBER
  • 3 POSTS
  • 1999 FORD F-150
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 225,380 MILES
My Service Engine Soon light came on and now my truck running bad. The problem is once I reach a speed of 20-35 mph the engine starts to running hard and seems as if it is missing and running ONLY on three too four cylinders. But once I reach and go beyond the above speed the truck or engine runs normal. After a few miles of continous driving it seems too reaches it normal temperature it will start running normal. I'm not sure what the problem is, but I need some help.
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Wednesday, September 9th, 2020 AT 6:26 PM (Merged)
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
Sounds like the ECT(engine coolant temp) sensor. But first have the codes read and post the results.
First thing you need to do is have the codes read, Post the results with the code number(s). Even if the service engine light is not on, there should be freeze frame data stored.
If it won't make it, buy a cheap scanner, they can be had for 30-40 dollars, a good investment, since they cover all cars sold in the USA from 96 on.
If the light is blinking, it means possible damage to the converter. Service it right away!
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Wednesday, September 9th, 2020 AT 6:26 PM (Merged)
Tiny
CURREN93
  • MEMBER
  • 3 POSTS
I had the codes checked and these are the results:
Code: PO 302 Misfiriing in Cylinder 2
Code: PO 401 EGR Insuffient flow
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Wednesday, September 9th, 2020 AT 6:26 PM (Merged)
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
Yep! Pull the egr off, clean the port under it all the way to the throttle plate, I use a length of steel coathanger. Put it all back together, reset the codes, if light comes on again, replace the EGR position sensor, thats the one the two small hoses from the exhaust plug into! P0302, Check the plug and the wire or boot if you have coil on plug system.
When was your last tune up?
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Wednesday, September 9th, 2020 AT 6:26 PM (Merged)
Tiny
CURREN93
  • MEMBER
  • 3 POSTS
My last tune was atleast six to eight months ago and I had the egr sensor changed then.
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Wednesday, September 9th, 2020 AT 6:26 PM (Merged)
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
Geat, but it's probably NOT the sensor, thats why I said to clean the port out, it'sloaded with CARBON, and is not Flowing, hence the insufficient flow code!
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Wednesday, September 9th, 2020 AT 6:26 PM (Merged)
Tiny
NOFD410
  • MEMBER
  • 2 POSTS
  • 1999 FORD F-150
  • V8
  • 2WD
  • AUTOMATIC
  • 17,600 MILES
My service engine soon light came on about 2 years ago and the truck has a hesitation around 50 MPH, a year ago a friend used a diagnosic tester on the truck and it gave us a code for a bad EGR valve so we did a tune up, we changed plugs, some vaccume lines, took off throttle body and plentum and cleaned them throughly but I did not change the EGR valve, the service engine light still remains on even after he turned it off with his tester, 2 days ago I started the truck in the morn. And the idle was rough, it felt like the truck was not running on all cylinders, I drove it to work and it ran bad the whole way, it was worse on an incline, today he checked the coils and we found 1 coil would not fire, so we replaced it and there was no change, than he replaced throttle positioning sensor, the truck ran better but the hesitation at 50 mph and on inclines still remains and the service engine light is still on, the fuel pump is the original and I changed the fuel filter about 5 or 6 years ago, anyone have any advise.
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Wednesday, September 9th, 2020 AT 6:26 PM (Merged)
Tiny
BLACKOP555
  • MECHANIC
  • 10,371 POSTS
EGRs when bad will cause bad performance on inclines, and since the check engine light has been on 2 years, it wouldnt put a doubt in my mind that the ports could be clogged and same for the egr.

Maybe new codes have accumulated, change the fuel filter get the engien scanned for codes and post back.
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Wednesday, September 9th, 2020 AT 6:26 PM (Merged)
Tiny
NOFD410
  • MEMBER
  • 2 POSTS
Blackop555, I changed out the fuel filter and the EGR valve, and the truck is running great, no more hesitation problems, the service engine light came back on today, the only thing left to change is the EGR Sensor, thanks for the info.
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Wednesday, September 9th, 2020 AT 6:26 PM (Merged)

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