My car (1997 Geo Prizm) is “jumping”, almost like random hiccups while either driving or still (park or neutral)!
It has been suggested that I just need to replace the spark plugs.
Does anyone know what is going on or what I should do?
You should pull out the owner’s manual (or get one) and look up all of the maintenance items that have been neglected. (Spark plugs are likely one of those things). Then you should have a reputable local mechanic take care of all of those things. If you still have a problem after having kept all basic maintenance up to date then you start looking beyond that.
Is the check engine light on?
Hold on, let me get my crystal ball out. Ok here it is. Yep, you have a misfire in cylinder #3 and the problem is a bad fuel injector. Have a nice day.
Hmmm, you are good, or is it bad, let me get my crystal ball, Oh it was a joke because you know the more information provided about maintenance performed can help provide a better answer.
Step #1 Get ALL the past due maintenance done. Then we can go from there. Not doing maintenance when due is a very expensive way of saving money. It will cost you a lot more than it will save.
To expand on what the others stated, it appears that the OP is attempting to “cherry pick” one maintenance procedure when it is very possible that a multitude of maintenance procedures are overdue.
This car needs to be brought up to date on ALL of its maintenance, rather than attempting to focus on just one part of the overall maintenance plan.
Is the car up to date on all of the maintenance specified in the Owner’s Manual?
If not, then you have a lot of work to do in order for it to run well.
How many miles on the plugs?
How many miles on the car?
Does the OP have the time or interest to follow up?
Questions in the mind of an old troubleshooter…