My 2010 focus rpm meter won't be stable ?
Unfortunatlet you'll need to take it to a shop and have it scanned to see what the issue is, it could be durty throttle body, bad TPS sensor, small vacuum leak or the Variable camshaft timing system
Check your timing and your vacuum system. It's called "loping" when it goes up and down.
Looking for a Used Focus in your area?
CarGurus has 64,428 nationwide Focus listings starting at $999.
Search Ford Focus Questions
Ford Focus Experts