rolla96

Hi Guys, I need some help with my 1996 Toyota 1.6 petrol Corolla 4A-FE engine (75k miles) which generally runs well, but I have noticed the engine “tick over” has started to increase, sometimes 1500 rpm even when it is hot. I took the car to a MOT testing station and was told it would fail on emissions. Whilst there I removed the fuel injection systems fuse to “reset” it. The emissions were rechecked and I was told it would pass and the tick over was back to 800 RPM. . RESULT !! Unfortunately this only lasted for a short time and then reverted back to high tick over and poor emissions again. The question is: what is making the fuel injection CPU set itself to an incorrect setting? Could it be the MAP sensor or the Lambda Sensor in the exhaust? Or something else? Has anyone else had the same problem and found a solution? A big thank you for your thoughts, kind regards Stu.