Welcome to MVS. It could be a sensor- but maybe not. You don't mention your miles and when the spark plugs were last changed. Sometimes basic maintenance items can cause your issues. If you think it's a sensor, have your trouble codes read with a san tool and see what comes up. 54k miles. Plugs hav...

Wife's 2005 S40 T5 has started dropping rpms when the engine is lightly loaded at around 2k rpms. Problem seems to be when engine is at a mid-range operating temperature. Never happens when engine is cold, and only once when completely warmed up. When problem occurs, pressing pedal to the floor will...