I'll give you the symptoms

[Gaard]

I drive a '01 Hyundai w/ 70,000 miles on it. Last night I raced to pick up my son at the babysitters - no probems with the car. On the way back home, the 'check engine' light started flashing and the car was jerking/skipping a lot all the way home, but it stayed running. No backfiring, just a lot of engine coughing.

Please tell me it's probably not the transmission.

 

[crosshairs]

If the engine light was flashing, its a misfire.
And a bad one at that..the light will only flash if the misfire is causing tailpipe emissions that will exceed the FTP standard..(Federal test procedure)

Plugs and/or wires would be my first guess.....

 

[funboy6942]

Tune up, or worse, if your car has a timing belt, it can be stretched throwing the timing off, and the jerking, sputtering, coughing, and on the verge of breaking. Those need to be changed every 60,000 miles, or what ever your manual says to do. If it should break some motors are not interference free, meaning it breaks, the valves stop moving, but the pistons dont, and it bends the valves and they come back up and smack them shut for you, causing even more damage, and a heftier bill.

BTW when the CEL flashes at you, something VERY bad has happened. In any case it needs to be checked out right away before something worse should happen.

 

[bruceb]

If the Check Engine Light flashed a few times, before it light up steady, then it detected an engine misfire .. had that happen to my car a while back. All it needed were new plugs & wires. If the check engine light just all of a sudden light up steady, with no flashing beforehand, then the code could be a serious one.

 

[iamwiz82]

Originally posted by: crosshairs
If the engine light was flashing, its a misfire.
And a bad one at that..the light will only flash if the misfire is causing tailpipe emissions that will exceed the FTP standard..(Federal test procedure)

Plugs and/or wires would be my first guess.....

Wait... What? The CEL normally flashes when there is a major issue. A CEL will only light up solid if it's an issue, but not critical. It doesn't have to be emissions.

 

[LTC8K6]

He means the misfire has to be bad to trigger the CEL, not that that's the only thing that will trigger the CEL.

I would guess misfire as well. Plugs, wires, or coil pack(s) if it uses them.

 

[cprince]

You should take the car to autozone for a free code scan.

 

[crosshairs]

Originally posted by: iamwiz82

Originally posted by: crosshairs
If the engine light was flashing, its a misfire.
And a bad one at that..the light will only flash if the misfire is causing tailpipe emissions that will exceed the FTP standard..(Federal test procedure)

Plugs and/or wires would be my first guess.....

Wait... What? The CEL normally flashes when there is a major issue. A CEL will only light up solid if it's an issue, but not critical. It doesn't have to be emissions.

The ONLY thing that will flash the engine light is an event that would put the tailpipe emissions past the FTP standard...also, the ONLY thing that will tun on an engine light is something that will affect emissions...weather its tailpipe emissions or evaporative emissions so yeah, it has to be emission related.
A transmission that wont shift will affect tailpipe emissions and turn the engine light on..a loose gas cap will affect evaporative emissions and turn the light on...but neither of them will cause it to flash .

 

[Gaard]

I had a guy from work come over and look at it & he asked me when the last time I had it tuned up. I told him that I had never had it tuned up - I have the oil changed 2-3 times a year and usually have them do the other stuff that they suggest, but I have never taken it to a shop to have it tuned up. He put some new plugs in (the parts store didn't have the plug wires) but it didn't help at all. He suggested that I take it down to Advance Auto to get some wires & while I'm there to ask them to hook up their little sensor reader to see what it says.

 

[crosshairs]

My guess is gonna be PO300 and a few other PO3** codes...

 

[Zenmervolt]

Originally posted by: crosshairs
The ONLY thing that will flash the engine light is an event that would put the tailpipe emissions past the FTP standard...also, the ONLY thing that will tun on an engine light is something that will affect emissions...weather its tailpipe emissions or evaporative emissions so yeah, it has to be emission related.
A transmission that wont shift will affect tailpipe emissions and turn the engine light on..a loose gas cap will affect evaporative emissions and turn the light on...but neither of them will cause it to flash .

According to the tech at the Volvo dealership it will flash also for certain items that will potentially harm the engine. Of course, that's kind of saying exactly what you're saying since pretty much anything that would cause emissions to go above FTP also has the potential to cause mechanical damage as well.

Like you, my money is on a misfire in at least 1 cylinder.

ZV

 

[Gaard]

I took it down there & it said cylinder 3 was misfiring. I put new spark plug wires in and the problem seems to have gone away (no more jittering). But the CEL (which was constantly blinking for the last couple of days) is now constantly on. I called the auto parts store up & he said that the CEL should reset itself after a while. Is this true?

 

[Zenmervolt]

Originally posted by: Gaard
I took it down there & it said cylinder 3 was misfiring. I put new spark plug wires in and the problem seems to have gone away (no more jittering). But the CEL (which was constantly blinking for the last couple of days) is now constantly on. I called the auto parts store up & he said that the CEL should reset itself after a while. Is this true?

You should be able to reset the light with the reader tool.

ZV

 

[dirtboy]

Originally posted by: Gaard
I took it down there & it said cylinder 3 was misfiring. I put new spark plug wires in and the problem seems to have gone away (no more jittering). But the CEL (which was constantly blinking for the last couple of days) is now constantly on. I called the auto parts store up & he said that the CEL should reset itself after a while. Is this true?

This is true for Chrysler products, but I can't say if it is true for Hyundai. Probably is. I think these things go away after 15-20 starts or so many miles driven without error.

 

[crosshairs]

Yeah, it will go out.....it takes time though depending on your driving habits.....After the misfire monitor runs 3 consecutive tests with no misfire detected, the light will go out...
Im not sure what the parameter is on that car to get the monitor to run, but highway driving is always good..
whatever you do, don't disconnect the battery..it wont turn out the light, but it will reset the adaptive numerator, then you gotta start all over again..

 

[Bignate603]

if you want to get it to clear immediately you can disconnect the battery. It worked on my Camry. However if you need to get it emission tested in the next week it could cause it to fail because the computer won't have a long enough history to know that the car is 100% ok.