Antwoord op "Why is it when driving the RPM gauge drops or jumps up?"My 2001 Honda Civic LX was already having an idling problem but would drive fine once you got to a constant speed. Then all of a sudden, the RPM gage stop working, it would barely go, sputtering very badly, air conditioner got warm & i thought I seen something fly off from my car in my rear view mirror. When I crank my car, for about 15-20 sec the rpm Gage goes from the 1 to 1 1/2like 13-15 times while making a clicking noise & then levels out. I’ve replaced the cam shaft sensor, spark plugs & throttle bottle position sensor. Also the battery light comes on when you first crank it & when accelerating on the gas it bogs down with a loud popping noise from the exhaust.