Rep Power: 0

Hello, I am writing because i just bought a 98 Civic LX.
It drives like new, purrs like a kitten and shifts gears fluidly.
But every once in a while (every 10-20 miles) it will give me problems;

The rpms will plummet down as im driving and the car wont accelerate (despite my foot steady on the gas pedal). I then step on gas hard and the car (and rpms) just races foward.

But if i dont give it a good step on the gas the rpms (as its plummeting during drive) will go from 3k to about 1k and the car will start to slow down (like i said, despite foot steady on gas the car wont maintain that speed, UNLESS i press hard on the gas, then it just races out)

Also, when that happens and the car goes back to normal (usually after 3-4 heavy footed steps on the gas pedal) the idle rpms (car in D4) will be as low as just above ZERO and the car will sound like its struggling to stay on.

I've taken it to a mechanic but it's hard to argue my point because the car never does it when other people are around, lol. And like previously mentioned, it only happens once in a while. The rest of the time it drives like a dream.

It has VERY low miles (47,xxx) so people have been telling me (that either they dont believe me because of how well it runs when they look at it or) that because of the low miles it has been sitting around too long and a simple tune-up would fix this.

It's still under warranty (60 days because of the low miles, ive owned it for about 2 weeks) but i dont want to have the dealer diagnose it for obvious reasons and the mechanics i have talked to thought i was imagining things (lol) and the other mechanic said it just needed a tune up.

I know very little about cars so I came here for help, thanks in advance.

 
Rep Power: 191

Check battery connections see if they are loose, also in the fuse panel there are 2 screws philips head screws that keep 2 metal plates held down if they are loose it can cause some issues as well. Now if there are any issues at idle then you need to clean the throttle body and the idle air control valve. While you are at it then check the chassis ground and engine grounds if they are loose or corroded then it can cause issues as well.