I have a 98 neon sport, which runs perfect. Until Thursday I went to start it and it was shaking and sputtering real bad. I drove it around the block and it never shut off, just had a little sputter to it, but still ran. Last year at this same time it did the exact same thing, except it broke down on me on the hwy..I brought it into the dealer and they replaced the spark plugs, and said the code on the computer was the multiple single cylinder misfire...same as code #43, and they said that was nothing that could be fixed?? Well today we replaced the spark plugs AGAIN and the engine light is still on! We started it and drove it and there is a differance, but i still dont want to drive it with that light on...please help!!!

Code 12 is a harmless code. It's just letting you know that the battery was disconnected at some point in your last 50 key cycles.

Code 43 is for a misfire. This usually is the result of a bad spark plug(s) or wire(s). Try changing your spark plugs first. If that doesn't help then try new plug wires as well.

Here's a link to what all the codes mean:

http://www.neons.org/neontsb/diagnost.htm

:)

I changed the spark plugs, it runs a little better, but the light is still on, along with the same codes. But the only thing is, I had those plugs changed last year...should they have already went bad, or could they have put bad plugs in there?

Try changing the S/P wires (2000 Neon, 100,000+ miles). Just changed mine, and that was the solution (had the same symptoms as your car). I had changed the plugs about a week ago, but the engine would still miss every once in a while. Then it got progressively worse every day to the point where I'd have to "feather" the throttle to keep it from sputtering. Climbing hills was even more challenging. Change the wires on your own...you could do it with your eyes closed, I promise. Good Luck.

I changed the spark plugs, it runs a little better, but the light is still on, along with the same codes. But the only thing is, I had those plugs changed last year...should they have already went bad, or could they have put bad plugs in there?

Typically plugs should be changed every 30,000 miles/2years whichever comes first. This also depends on what kind of conditions are in your area as well. For example I live in a hot climate, where heat is so hard on cars. I have to change hoses, parts, filters etc more often than someone who lives in a milder climate. The code 12 is harmless. For the 43 though, did you make sure the plugs were gapped properly? If so then the next step would be to get the spark plug coil pack tested.

The plugs have been changed and also the wires...the light is still on...but I drove the car last night and it ran perfect, almost like nothing is wrong with it, except that stupid light!!! Anything else I can do on my own, without bringing it in and paying an arm and a leg????

Typically plugs should be changed every 30,000 miles/2years whichever comes first. This also depends on what kind of conditions are in your area as well. For example I live in a hot climate, where heat is so hard on cars. I have to change hoses, parts, filters etc more often than someone who lives in a milder climate. The code 12 is harmless. For the 43 though, did you make sure the plugs were gapped properly? If so then the next step would be to get the spark plug coil pack tested.

I have a question for KatWoman, and maybe the answer will help JessicaC. I had taken my car in to a repair shop last week for a "stumble" in the engine, as well as my Check Engine light being on. A cam timing sensor was changed, and so the problem was fixed. But the day before I took it in, I replaced the plugs (even though they were ok) and cleaned the battery terminals. The Check Engine light had gone off after doing this. So finally, here's the question. Is it possible that the computer reset itself after the battery terminals were disconnected, and that's the reason the CEL turned off? Maybe JessicaC should try disconnecting the battery and see what happens? I know it might sound far-fetched, but may be worth a try? Just Curious, Thanks :)

Just be patient with the light, it will go out once you turn the ignition so many times. If the battery isnt disconnected within that period; and providing everything else is fixed

Maybe I'll just try my dads suggestion for the problem..black electrical tape over the light!!! I'll run it for awhile, on short trips to see how it runs, I'm still a little nervous about longer trips...thanks for all your help, I'll keep you all updated.