Check engine Light

Lets use this guide to see whats going on.

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

Please run down this guide and report back.

the codes that come up are dealer only codes they want $600.00 to tell me what the problem is.

You can check your codes for free. post the number here so we can fix it.

99 ford expedition, recently replaced coolant bypass hose. before I replaced the hose, my serv. engine soon light came on. After replacing the hose, the light went off & came on again after driving about 2 miles. Its been a week & it remains on. A mechanic told me to use water only for a week (after replacing hose) then drain the coolant & put back all coolant. Will that cause my engine light to remain on due to having been running on water only? will my light shut off with coolant in the system? How severe can this problem be? I cant pass a smog! I recently replaced the engine too! it runs a bit rough now.

Straight water won't cause the check engine light to come on. As far as the doing this, it is a cheap way of flushing dirt from the system. Keep in mind, water will boil before coolant.

I got an oil change and then my service engine soon light came on and the truck is now running rough and idle's rough. I took it back to where i got an oil change and they said it was my fuel injectors so they put fuel injector cleaner in the gas. They then turned the service my engine soon light off but after driving about 5 miles it came back on. I took it to Auto Zone and they told me it was a misfire in cylinder 1. Should i get fuel injectors cleaned or should i take it to the dealer and have them test it.

You are not also having engine noise like a load knock by any chance? But look at the #1 ignition coil connector and fuel injector connector to see that it was not knocked loose by accident? If it looks ok remove the #1 coil and inspect the boot especially on the inside and look for carbon tracking. If you see the boot is bad you may be able to replace just the boot by itself without having to buy the whole coil. If it looks ok put coil back in but do not put the hold down bolt yet. Start the truck and gently pull up on the coil. Do not remove it out completely as you can get shocked and it hurts. If you hear a continouse popping sound then your coil is ok. If you hear nothing then your coil itself is bad. If all that is good remove the spark plug and inspect for damage around the ceramic. Beyonde this point you will need to take to have it diagnose. Other possibilities for misfire could be a bad injector, low compression due to bad valves or piston rings so you would need proper equipement to do the proper testing.

my service engine light came on at rhe same time as the o/d light started flashing, then the truck made a loud flutter noise almost like it was about to cut off but did not, what does that mean?

It could be many things. If the check engine light is on, there will be a trouble code stored in the computer. What I recommend it to take the car to a nationally recognized parts store and have them scan the computer for codes. The code will identify where the problem is coming from. Let me know what the code is and then I can better help you.

Joe

After I repaired the problem (replace coil and wire on number 8 cylinder). When will the service engine light go off? Does it clear itself or do I have to clear it?

It may or may not reset. Take it to a nationally recognized parts store and have them scan the computer then ask them to reset the light. Most will do it for free.

Joe

1998 Ford Expedition

I just got a tune-up should my car be jerking and should my check engine light be on already?

No it shouldn't. What all was done for a tune up, what size engine do you have and I need you to do one more thing. Take the car to a nationally recognized parts store and have them scan the computer. I need to know what trouble codes are store in the computer. Most parts stores will scan it for free, so let me know what you find. Also, I would let the people who did the work know there is a problem, but wait until you tell me what the trouble codes are so I can tell you if it is something they did.

Joe

I have a 1998 ford expedition 4.6 L, W motor, got a engine diagnosis test done becuase of a rough idle when in park and backing up, had exhaust smell and alot of smoke coming out of tailpipe. whiteish until care warmed up. , paid $90 for test and it read code PO135- 02 sensor heated bank/sensor/ also PO401 egr, dpfe sensor, and p1131 lack of heated 02 sensor bank/sensor, switch indicated lean, cycl. 2 mis fire. I replaced the 02 sensor on the passenger side the one up front that they said. I also replaced the egr and dpfe. The engine light is still on. has a little miss yet when at idle only. I had a remanufactured engine put in about 7 months ago. Im getting stressed out about this issue. I dont know alot about vehicles and having a hard time who to trust. Ford isnt helping. I dont want to uin the engine that was just put in. Any suggestions what the issue might be.was there 2 sensors i was suppose to replace . truck running a little better but like i said light still on and little hesitation or miss when idling. help please if you canI have 207,000 on vehicle about only 6000 miles on remanufactured engine so far

Fault codes never say to replace parts. If it was that simple, we wouldn't need mechanics. They only indicate the circuit or system that needs further diagnosis. There can be a corroded connector terminal, bare wire, emissions passage plugged with carbon, and lots of other causes for a code other than a bad sensor.

The white smoke indicates burning coolant. If the coolant level has been dropping in the reservoir, suspect a leaking head gasket. If the level is fine, you might be seeing normal condensation burning off when you start the engine. Regardless, the cause for the misfire should be diagnosed first. I suspect the codes you're getting are from the sensors reporting the results of that misfire, not causing them.

like i said i dont know much about cars. Im kinda illiterate about them. I just dont want to get taken advantage again. If im replacing these parts an it shows back up on a diagnosis whats the deal and what do i do next. Check the plugs, coil what, idk. i appreciate your info.

The codes indicate the circuit that needs to be diagnosed. After the diagnosis is when a part is replaced if that's what's needed. You're replacing parts before the cause of the problem is diagnosed. That's the most expensive and least effective way to fix a problem.

The oxygen sensor codes could mean that side of the engine is running lean. You don't replace the sensor just because you don't like the problem it reported. One thing to keep in mind is when you have a misfire it is due to loss of fuel, loss of spark, or loss of compression meaning an engine problem. The most common cause is loss of spark. That means unburned fuel and air go into the exhaust system where the oxygen sensor detects the unburned oxygen. You might smell the unburned fuel at the tail pipe but oxygen sensors don't detect fuel, just oxygen. Depending on the strategy of the Engine Computer, it might command more fuel to that side of the engine in response to thinking it's running lean. That will make your fuel mileage and engine performance even worse, and no matter how much extra fuel it adds, there will still always be that unburned oxygen getting detected.

Another common problem that only occurs on Ford trucks is a plugged EGR emissions tube. The passages become plugged with carbon. If the passage to one cylinder is plugged, only fresh air and fuel will go into that cylinder and it will be fine. As more and more passages to different cylinders become plugged, pretty soon all the exhaust gas is routed to the one remaining cylinder where its passage isn't plugged yet, and since there's so much exhaust gas going into it, there's no room for fresh air so that cylinder misfires. As far as the EGR tubes are concerned, the one going to the misfiring cylinder is the only one that isn't plugged.

Those are just a couple of examples of what can happen. As I mentioned previously, wiring problems are just as common as sensor problems. A bad sensor will be the cause of setting a fault code only about half of the time. Their purpose is to monitor specific aspects of the engine, and when they set a code because something is wrong with the way the engine is running, they're doing their job. Replacing them isn't going to help.

okay, heres the newest. I ended up having a cracked head. dealer replaced it. Now engine light stayed on. I took back and they replaced a 02 sensor and cleaned my egr port. Light went off but truck still is missing when im at a idle or in park. Like it wants to stall. I still think egr valve. but i dont know. Do I take it back to them with this issue or what else can it be.

Absolutely take it back. They deserve the chance to check their work and correct any mistakes. There can also be other additional defective parts that didn't show up previously. Spark plugs are good for that but that's just one example. Depending on what they find, if a new part is bad or if they did something wrong, you should not be charged, but if some other part is bad it is perfectly legitimate to expect you to pay for it, but very often they will not charge you for the diagnosis and / or labor. There's nothing unethical about charging you for the labor if they didn't do anything wrong last time, after all, no one else works for free, but in the spirit of customer goodwill, and as a way of apologizing that you had to come back so soon, they will often overlook additional labor charges. It depends on the marketing mentality of the shop. Some want to squeeze as many dollars out of you now because they know you're never coming back, (typical GM dealership), and some build customer loyalty by charging more fairly so you come back often, (typical Chrysler dealership). Ford is in the middle of those two extremes.

My check engine light came on, so I ran the diagnostic at an auto parts store and it said bank 1 sensor 1 had to be replaced. I know that means that it's the upstream oxygen sensor but I don't know where it goes, can you send me instructions and a diagram please.

Diagnostic fault codes never say to replace parts. They only indicate the circuit or system that needs further diagnosis. In the case of the oxygen sensors, there's about a dozen different codes related to them and most have to do with problems in the wiring or that the sensor is reporting a bad condition. You don't automatically replace the sensor when it has detected something wrong. Do you know the exact code number or the exact description?

Hi
The check engine lite in my 1998 Explorer came on a few days ago and is still on. what worries me is in Sept. the light came on and i took it to Ford and they said the cam shaft sensor needed replacing, so i had it replaced. I thought my worrries were over.Now the light is on again. Last week before the light came on I had the oil changed, transmission fluid changed and coolant changed. My vehicle needs its first tune up at 100,000 miles, i am wondering could this be why the light is on?

Hi:
What I suggest is to take it to a nationally recognized parts store and ask them to scan the computer for codes. Most of these stores will do it for free, and they will be able to tell you what is wrong.

Let me know what you find.

Joe

hard starting,rough idle, hesitation at acceleration, idler pulley at top left not turning just rubbing on belt.

Hi:
The engine running problem you have most likely has to do with a coil pack. You mentioned that the check engine light is on. I recommend taking it to a nationally recognized parts store and have them scan the computer. It will provide codes that will indicate the problem. As far as the idler pulley, you should replace it. It will damage or break the belt.

Joe

Driving down the road engine started sputtering, only at cretain speeds, check engine light came on. seemed to come and go-i did make it home...Where do I start?

If the light came on, take it to a nationally recognized parts store and have them scan the computer for codes. Most will do it for free, and you will know where to start.

Let me know what you find.

Was just driving down the road and a check engine light came on.

Drive to your nearest AutoZone or Advance Auto and them will retrieve those engine trouble codes. usually they will do it for free.

The problem I'm having is that at lower RPMs, the engine runs rough, and it doesn't matter if it's in gear or at idle. I'm not much use on the newer vehicles, but it acts like it has a fouled spark plug, but whatever it is causes the "Check Engine" light to come on, and sometimes flash. I've had two AutoZones and a Jiffy Lube try to connect to the computer port under the dash, but their hand held devices aren't producing any codes. After doing some checking, I've been told that it's a possible coil pack issue, but I wanted to make sure before I just start replaces parts.

Thanks for the help!

this is easy ..cuz u were barking at the wrong tree...engine driveability and perfomance emission is my specialty ..I'm an L1 tech ...no sweat..lets try the easy thing 1st ...lets understand what trigger the chk eng lite..
when the chk eng lite come on ...make sure it stay on or don't cut off ur engine before some1 scan it ..u might have a bad grd or pwr that kept wiping out the memory code after u turn it off..try this 1st ..
NOW!!!..if u still can't get a code on generic OBD2 code reader..that means it is a factory code..u gonna need a real mechanic ..opsssed i shouda say real tech with either a ford factory scan tool or after market like a snap on- modis,solus or OTC genisys which are capable to extract factory code ..
get the code and let me know ..then we go from there ...
BY government rules ..if ur chk engine lite come on...all manufacture ECM must be able to STORE A CODE .....get more detail on OBD2 codes and system on internet b4 u listen to parts guy or lube tech...let me know and good luck man

hello i am truly frustrated with this light! i have changed coil packs, spark plugs, o2 sensors, air filter,cleaned the intake and flushed and cleaned the injectors i am in desperate need of an answer PLEASE HELP!!!!!!
i got the vehicle scanned and it is telling me BANK 1 IS RUNNING LEIN . what can i do to resolve this problem ???
JOSH MORRISON

That would usually mean that THe bank one O2 sensor is bad. do you notice any driveabliity problems? reset the light see if it comes back.

i did reset the light it did come back on i just repalace my K & N filter back to a paper filter hopefully that will resolve the problem. i did start having problems when i switched it out also the K & N did not sit well inside the housing i will let you know in a day or two

that may help! good luck and hapy hunting