I have O5 Focus ST 2.3L manual transmission with 95,000 miles. When shifting between gears the rpm's will shoot up to around 2000 to 2700. (Foot not on the gas) Rpm's will only come to normal at a full stop. My mechanic cannot find any vacuum leaks. Mass airflow sensor has been replaced as well as the idle air control valve, and spark plugs. Throttle body is cleaned and appears to be functioning properly. My mechanic claims it still could be my Throttle body or the pcm maybe ecm cannot remember. This car has so many sensors, hoses, and lines just the intake system its confusing.
Any suggestions? Or just live with.
Has it been scanned for codes? Maybe recorded live data when the problem happens to look for clues?
It gave me a generic code for high idle. I had my mechanic look at it. I have not done live data though I'm not savy enough to read what i would be seeing. I have heard the timing chain cause an issue like this but figure that is not the case seeing when at full stop idle returns to normal. I will see if my mechanic will do a live data scan.