94 NewYorker unnecessary roughness

Hello....thought I'd get some feedback here before I take my car to the
station.

Two/three weeks ago I noticed a roughness or hesitation while driving.
It usually appears when taking my foot off the gas or while driving at
slower speeds, say 30-45 mph. It's not extreme but it's definitely there.

Then a week ago my check engine light came on once and stayed lit til I parked. It didn't come on again til last night driving home and its off again this am.

Can anyone steer me in the right direction as to what I should look at?

It would be much appreciated.

Thanks
Jeannie




























































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Hi, welcome to AF!

There could be a variety of reasons this is happening but for starters lets start with why the Check Engine light came on as it may be related with your roughness problem. Everytime the check engine light comes on (and sometimes not) the PCM will store a code relating to a problem it has detected, what you need to do is check for fault codes stored on the PCM so we have an idea on what is going on, this can be easily done without going to a dealer to retrieve them.

You will need a piece of paper and writing instrument to write the codes down and your ignition key. To retrieve the codes, in a rapid sucession turn your ignition key to the on position, then off, then on, then off, then on and observe your Check Engine light. It will stay on for a moment then go off for a few seconds, then it will start flashing on and off, count the flashes (the number of times the light illuminates), all codes are 2 digits, meaning it will flash the first code's digit, pause for a moment, then flash the second digit. Then it will pause again and if there is more than one code it will start flashing the second code. The example below is the sequence for a single stored trouble code.

on-off-on-off-pause = 2
then on-off-on-off-on-off-pause = 3
Trouble code is 23

on-off-on-off-on-off-on-off-on-off-pause =5
on-off-on-off-on-off-on-off-on-off-and stays off =5
Code is 55

You will ALWAYS get 1 code if no faults are stored in the PCM and that will be code 55 which means "End of message", any other codes flashed before code 5-5 is a trouble code, you will get more than one code in this case because the Check Engine light was on recently. Then turn the key back off and wait a few minutes and repeat the procedure to verify what codes you received on the first try. Give this procedure a shot and post back here with the code(s) received and then we can continue.

That is the coolest thing!!!!!!!! I got a: 12, 21,55

Now what?

Thank!!!!!! YOU!!!

to AFHi, welcome !

There could be a variety of reasons this is happening but for starters lets start with why the Check Engine light came on as it may be related with your roughness problem. Everytime the check engine light comes on (and sometimes not) the PCM will store a code relating to a problem it has detected, what you need to do is check for fault codes stored on the PCM so we have an idea on what is going on, this can be easily done without going to a dealer to retrieve them.

You will need a piece of paper and writing instrument to write the codes down and your ignition key. To retrieve the codes, in a rapid sucession turn your ignition key to the on position, then off, then on, then off, then on and observe your Check Engine light. It will stay on for a moment then go off for a few seconds, then it will start flashing on and off, count the flashes (the number of times the light illuminates), all codes are 2 digits, meaning it will flash the first code's digit, pause for a moment, then flash the second digit. Then it will pause again and if there is more than one code it will start flashing the second code. The example below is the sequence for a single stored trouble code.

on-off-on-off-pause = 2
then on-off-on-off-on-off-pause = 3
Trouble code is 23

on-off-on-off-on-off-on-off-on-off-pause =5
on-off-on-off-on-off-on-off-on-off-and stays off =5
Code is 55

You will ALWAYS get 1 code if no faults are stored in the PCM and that will be code 55 which means "End of message", any other codes flashed before code 5-5 is a trouble code, you will get more than one code in this case because the Check Engine light was on recently. Then turn the key back off and wait a few minutes and repeat the procedure to verify what codes you received on the first try. Give this procedure a shot and post back here with the code(s) received and then we can continue.

21= oxygen sensor voltage not fluctuating. Since you have a pre-96 vehicle, you should 1 or 2 sensors, so go on and replace the oxygen sensors.

21= oxygen sensor voltage not fluctuating. Since you have a pre-96 vehicle, you should 1 or 2 sensors, so go on and replace the oxygen sensors.


Ok...So... Is this something I can do? Are there any websites that will give me some basic help?

And what does the other code mean? The 12? I really appreciate the help.

Thanks
Jeannie

If you have any automotive experience and know how to replace oxygen sensors, you can do it, it's just tricky. I recommend going to a trust mechanic and let him do it, he has the right tools for the job. Code 12 means that your battery has been disconnected recently, nothing major.

12 means that the car battery either was dead or had been disconnected.