The car is V6 and has a computer that monitors faults. The engine omissions light comes on temporarily on a regular basis, particularly on hot days & when this happens there is less power on acceleration & the car appears to drag until the light goes off. This has been occurring since I bought the car over two years ago & we've been told it's due to the knock sensor & the computer just needs resetting. Lately the car has felt like it's dragging even when the light isn't on, & the power to the wheels when pulling away is difficult to get right as a result, causing the car to skid frequently even when it's dry. After skidding the engine cuts out, but only for a few seconds, it does not completely die & need to be restarted. Yesterday when I was driving home from work, just after the engine had fully warmed up, it began revving to just above 3,000 when I was stopped or going below 25mph, as if I was pumping the gas pedal up & down. It did not change by having the car in or out of gear, & was not affected by whether or not either the gas pedal or clutch were depressed. The performance seemed not be be affected but the engine got hotter than usual. The revving stopped once the car was going at a certain speed, but started again as soon as it was decreased. I think that whatever is causing it is probably related to the lack of power at other times & the difficulty in getting the clutch to gas ratio right every time when pulling away.