mustang running rough

[Get some 5.0]

Something went wrong today coming to work. My 5.0 started showing a check engine light. I does not stay on, but the car is running rough as hell.
Has anyone had this problem or does anyone have an idea what it could be. I put the car back to stock and it still does it.

 

[Bad Intention]

Run the diagnostic check with your hand held. See what it says.
You may have some bad gas.

 

[Get some 5.0]

Ok thxs, I was gonna take it to the dealship in the morning. Which I will have to argue with them cause there gonna say it was my tune.

 

[Get some 5.0]

The check engine light stayed on and my SCT said that I have a #8 cylinder is misfiring. I will let the dealership find out if its the coil pack or spark plug.

 

[h34d]

The check engine light stayed on and my SCT said that I have a #8 cylinder is misfiring. I will let the dealership find out if its the coil pack or spark plug.

This will interest you.

clicky>>>[ame=http://forum.grrrr8.net/showthread.php?t=22082]Random misfire[/ame]

 

[chrisheltra]

Could it be a malfunctioning knock sensor?

 

[h34d]

This will interest you.

clicky>>>Random misfire

For those of you who don't want to click the link the only time I've heard of a similar problem the fix was replacement of the ECU.

quote from that link from wnt2gofst - "Ok. I think it is fixed.

Today took in replaced computer down loaded software reset misfire calibrations. Drove about 100 hard miles no issues.

Usually it's kicked on by now. So far so good."

I don't think his car was "running rough" but was just flashing a MIL.

 

[Get some 5.0]

Well the dealership called and said it has low compression in #8 cylinder 16%. Waiting on further word to tear motor down. A engineer might come and look at it, cause its such a new motor with only 5700 miles on it. Didnt say anything yet about my Steeda CAI, or tune. I dont know it they can see the tune, I returned it back to stock!!!!

 

[chrisheltra]

I dont know it they can see the tune, I returned it back to stock!!!!

Rest assured they can tell if its been tuned. All you can do is hope they dont care. Sorry to be such a Debby Downer

 

[01Lowboy]

rest assured they can tell if its been tuned. All you can do is hope they dont care. Sorry to be such a debby downer

+1

 

[JL-KA]

What they can see is that the car was reflashed 'x' number of times and if they look they will see that it doesn't match what they have in their records. At that point you'll start getting into trouble.

 

[chrisheltra]

What they can see is that the car was reflashed 'x' number of times and if they look they will see that it doesn't match what they have in their records. At that point you'll start getting into trouble.

They can also see the date. IIRC

 

[JL-KA]

Was not aware it showed date.

This is why I would never tune a car under warranty unless you've can cover the cost of a new motor. There's plenty of appearance stuff you can do to keep you entertained.

 

[5.0jake]

Rest assured they can tell if its been tuned. All you can do is hope they dont care. Sorry to be such a Debby Downer

Do you know for a fact they can tell or are you assuming?
This is why I have been holding back on getting a tune with all of this conflicting info out there.
There are multiple threads saying they can't tell any thing if it's been flashed back to stock...:shrug:
Info from other threads have said it only looks like the battery has been unplugged and that's it. Put it back to stock and drive a while, they won't see anything. One said there was a time stamp and people quickly came in and said BS.
What are the facts?!oke:

 

[chrisheltra]

Do you know for a fact they can tell or are you assuming?
This is why I have been holding back on getting a tune with all of this conflicting info out there.
There are multiple threads saying they can't tell any thing if it's been flashed back to stock...:shrug:
Info from other threads have said it only looks like the battery has been unplugged and that's it. Put it back to stock and drive a while, they won't see anything. One said there was a time stamp and people quickly came in and said BS.
What are the facts?!oke:

I know for a fact that they can. I was told straight from the lips of Ford. I had to spend $900 years ago while my L was still under warranty for a new ECU because they sent it back to Ford and it was found that I had installed a tune on it. I never told them it was tuned and I know it wasnt a lucky guess.

I have also been told by Ford employees that they have the means to test your motor oil and test for traces of burnt n2o in case you blow your motor for some unknown reason while running n2o they know whether or not to honor the warranty.

 

[5.0jake]

Interesting.
A guy on this thread (2011gtnick)said he worked at Ford don't worry about, he sounded pretty convincing.

Warranty and upgrades - Page 2 - Ford Mustang Forums

What you said sounds convincing as well.
Would the service dept know if your car has been flashed with their own diagnostic tools if your ecu wasn't sent back to Ford?

 

[chrisheltra]

Interesting.
A guy on this thread (2011gtnick)said he worked at Ford don't worry about, he sounded pretty convincing.

Warranty and upgrades - Page 2 - Ford Mustang Forums

What you said sounds convincing as well.
Would the service dept know if your car has been flashed with their own diagnostic tools if your ecu wasn't sent back to Ford?

I didnt read the thread but I have first hand experience that they can. If your willing to risk your warranty by all means get a tune. My car will stay stock until they find a fix for the manuals trans issues.

It also depends on what kind of service writer you get some are more lenient than others.

 

[JL-KA]

To be fair though that was with a Lightning many years ago. They may have changed how the PCM functions.

 

[chrisheltra]

To be fair though that was with a Lightning many years ago. They may have changed how the PCM functions.

Ill agree but the possibilities of them taking functions out of PCM's over the years is doubtful if anything Id be willing to bet theyll have more info on the install of your aftermarket tune then they did back then. 8 years does wonders for technology. :thumbsup:

 

[Sir Nate 3000]

To be fair though that was with a Lightning many years ago. They may have changed how the PCM functions.

The PCM's are more advanced now, a lot more information is saved and can be read!