My mom has a 95 rebuilt Neon- therein lies the problem I think. Anyhow, it has several problems that I am HOPING above all hopes that someone here can help me with.

First of all, the most important issue is with the way it runs. When you first start it up, it shakes like something awful. It is a borderline violent shaking/extremely rough idling. Also, when you are driving down the road, it will continue to accelerate even after you have taken your foot off the gas. Then for the last issue - which is probably an obvious problem - the gas mileage IS AWFUL! On top of all that - the check engine light is on - so something is definitely wrong.

I have done all the simple maintenance such as change the oil filter, change the oil, replace the air filter, and replaced the spark plugs.

Now I am beginning to wonder if the firing times are off - and how I would fix that.
AND if maybe the O2 sensors are shot.

-Any other problems that it could be?-

Now for the electrical problem. Almost right after we bought it, the speedometer stopped working. Shortly thereafter, the tripometer and odometer stopped working as well - so it likely has more than 99K miles, but that is what the odometer read this morning :P

Every now and then, they will intermitantly start working again. Leaves me to believe that there is a loose wire/short/or a bad connection somewhere(sometimes it will work when you beat the dash - but I don't advise doing it while driving). When we took it to the shop, they didn't find anything. They replaced the sensor that controls this, but that didn't work.

Like I said above - it is a 95 dodge neon, 99K miles, 5 speed.

 

I went out and did the self test following the directions in the " My neon is sick...help!" post.

I didn't quite get all the codes, but there were a TON! :S :S

I think I am going to go out and get them right now and call the dealership - I would say there were about 4-5 codes that thing shot off.

 

Sounds like your in for a good bit of fun with all that...[:@]

 

fun doesn't even begin to describe it [:@]

I got the codes- I got 5 codes []

I called a dodge dealership and asked what the codes meant and he said he didn't have any info on the following codes:

12;43;43;21;51 (Yes, I got 43 twice)

this leads me to believe that the idiot that rebuilt the car - put the wrong bloomin computer in the thing- what do ya think?

 

Oh, and if anyone is nice enough to try and ask a dealership near them, I would appreciate it a TON. I live in Chattanooga Tennessee and the dealerships aren't know for there 'helpfulness'

If someone has a shop and can figure out what these diagnostic codes mean - that would be even better!

It is a 1995 Dodge Neon, 4 cyl (of course), 5 speed.

Computer P/N: P05289709 - it is a Chrysler computer, which doesn't seem right cause it is a dodge model '95

 

We'll start with the obviuos one,

43 Multiple/ single cylinder misfire
21 02s sensor problem (oxygen sensor), upstream or down stream
51 Fuel system lean

Ok, miltiple cylinder misfire is in direct relation to your oxygen sensors being bad. I'm guessing it's the upstream sensor. But I'm willing to bet the downstreem is also bad. Replace both of them.
Change your spark plugs, and your wires. They are fouled.
You are getting a code 51 because of the misfire and the oxygen sensors are bad.

The code 12 is nothing to worry about it's just telling you the battery has been disconnected within the last 50 key cycles and it's always there.

And yes, that should be the PCM for your car. The codes have nothing to do with the computer. So, don't worry about it.

And the reason why the dealer won't tell you what they are is because they aren't making $$$ off of it.

 

Oh, forgot to mention, once you replace all those things what you are going to need to do is disconnect the negative battery cable fromt eh car for 30 minutes to an hour to reset the computer.

 

THANKS. Lifesaver. I knew the O2 sensors were bad, but I had no idea about the rest

 

Nop problem. Good luck.

 

hmmm, my dads truck seems to be misfiring and earlier in the year autozone said that ther are 3 o2 sensors and they dont know which one or how many are bad but we never thought that maybe the o2 sensors had something to do with misfiring...(we never changed the 02 sensors...at least i dont think he did)