The other day I had; a RENAULT MEGAN 1600 16V Customer complaint that the car is cutting out when she go around a corner or when she approached a red light. or stop street. She could start the engine immediately and would go on without any troubles. I took the car for a test drive and found that the car is not pulling strong, as if one of the ignition coils is not firing. There is a lack of power. The engine would sometimes cut out at stop street or if one goes around the corner. Pulling away also was not smooth.
To cure the problem I have done the following:
1. I have removed the ignition coils and tested them with a coil tester, they test all OK
2. Test the fuel pressure it is OK.
3. The next thing I have noticed was that the MAP (manifold absolute pressure) was very loosely as if the o rings were worn. I tried to remove the MAP sensor but the front part broke off and I had to remove the front part from the intake manifold. Once I got it out I use super glue to reassemble the front part to the MAP body.
4. Diagnose tests show no codes, so this makes it more difficult.
I took the car for a test drive and it performed much better, the engine is not cutting out anymore and performance is back to normal. The MAP sensor must have been cracked just above the o rings causing the engine to cut out and cause the engine to perform poorly.
It would be good practice also to clean the throttle body.