service engine soon light

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.

well my engine light come on couple of months ago and i wonder why it come out?? so if some one could tell why it come out please

Check engine light:

Have the computer scanned for code/s-you have a problem within the engine management system that caused the CEL to turn on-This is your starting point of diagnosis,finding out what's going on.

well am do that too, and im guessing its going to be the transmission but thanks :)

could a broken or cracked pcv valve/tube cause a PO 171/ PO 174 code to come up? truck runs like new. we're just really irked over this service engine soon light.

Among other things, yes a faulty PCV component can cause these codes. Also check EGR ssytem, ensure engine oil is not overfilled, MAF sensor needs tested, leaky fuel pressure regulator or sticky/dirty fuel injectors..

I am a long time certified auto tech and I'm at a dead end.
I have had this same problem for the past year or year and a half. My truck is throwing codes for O2 sensors being too lean. It isn't making sense. I have replaced the upper plenum, MAF twice, DPFE three times, EGR, and both pre-cat O2 sensors twice.
I have checked for vaccuum leaks and post-MAF air leaks...found nothing.
I am still getting the same symptoms of racing at startup and surging (RPM up and down) at stop lights/signs (mostly when it's cold.
What might the next step be other than taking the truck through the dealership window?

When replaced intake gasket did you reuse the port gaskets and isolator bolt assemblies ?
the new isolator bolt assemblies use a green rubber if you used the black color its no good and have to be replaced
and while you have it out check EGR tube and port they do get plugged
you can use carb cleaner or similar solvent and small screw driver to clean it

[quote:9debfcc0d1="BMRFIXIT"]When replaced intake gasket did you reuse the port gaskets and isolator bolt assemblies ?
the new isolator bolt assemblies use a green rubber if you used the black color its no good and have to be replaced
and while you have it out check EGR tube and port they do get plugged
you can use carb cleaner or similar solvent and small screw driver to clean it[/quote:9debfcc0d1]

I did use the new port gaskets and isolator bolt assemblies. I'll double check the EGR tube and port, and one other thing I've noticed is that the PCV can get sticky or plugged...I'll give that a shot too.

Thanks

Well, I've checked the EGR ports and tube, was cean...I made sure they were clean when I replaced the EGR valve...but I double checked anyway. The PCV wasn't in the least bit dirty or plugged.
It's still acting up and I'm still at a loss.
One person (wont mention where this person was), suggested flashing the computer...That would be a last resort so I would prefer to try other possible solutions if possible.

We always let flashing the PCM as a last
I dont recall having much of an issue with an EGR or acting up
we had a lot of intake gasket failure causing running rough and check engine light on with misfiring codes
Sorry I will try and locate up more for you
just can you get me the codes on it

I will get those for you. I'm currently at work and will sleep tomorrow during the day, so I won't have a chance to get those codes for a day or 2.

the codes for the first 5 or 6 times were:

P0171 System Too Lean - Bank No. 1.
P0174 System Too Lean - Bank No. 2.


The codes for this last time are:

P1137 Lack of Downstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1.
P1157 Lack of Downstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 2.

i bought a 2002 ford f140 with 92000 miles on it. Today the engine light came on, what can that mean?

The Engine Computer detected a problem that could have an adverse affect on tail pipe emissions. Many auto parts stores will read the accompanying stored diagnostic fault code(s) for free. They will lead you to the circuit or system with the problem, not necessarily the defective part.

caradiodoc

Having the computer readout by Autozone says the EGR valve is bad again. I say again because I have replaced it less than a year ago and previously the year earlier.

I have been downsized and so need to do this work myself. Is there something I could have done to to cause the EGR valve to fail or could there be something causing the failure?

Try checking the rest of the DPFE/EGR as you see below:

Had the same problem # 4 in the diagram above, EGR pressure sensor needed to be replaced. Sometimes a little particle gets on it from dirty fuel especially after that many miles, I only had 70k when mine went out. Change it have the service light shut off and see if that works.

Poor gas mileage and check engine light came on.

Check engine light on

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

Have the computer scanned for code/s-you have a problem within the engine management system that caused the CEL to turn on-This is your starting point of diagnosis,finding out what's going on

I recently changed the battery in my F 150. When I drove for about 20 miles, the check engine or emission warning light came on. I checked the manual it read that i was supposed to let it idle and drive it for 10 miles so the truck can relearn its idle trim. I also noticed a hesitation in the truck when idleing.
Is this warning light have to do with not changing the battery properly?
What can fix?
Is it normal?

THe battery or alternator light will come on if there is a problem with charging. What I recommend doing is taking the vehicle to a nationally recognized parts store and have the scan the computer for codes. Let me know what you find.

our 2002 F150 has a service engine soon light on. we had it scanned and came up with 2, PO171 and PO174. the problem is we don't know if the vechicle has 1 or 2 O2 sensors. Also when checking the pcv valve the is very little vacuum. could this be the cause of the codes?

you need to know exactly how much vac you have should be beyween 18 and 21 inches of vac if not suspect exhaust convertor or muffler. these could be false codes if it is running bad you will always have these codes. and you have atleast two 02 sensors

the truck will run good for awhile then it will start missing the check engine light will flash then it will run good for a mile or two. it will come and go all the time.

you need to check it for tune up as a 1st step the blinking check engine light indicating a misfire
you need to get the PCM scanned for codes
that will help pin point the troubled area or cylinder




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