I’m having big problems with my valver in that it is starting to cut out when idling, even when the engine is warm. It just dies and when I try to restart it the engine turns over but doesn’t catch for a while. I have a full exhaust system, de-cat and IK but nothing else. It hasn’t been serviced for a while but has recently been on an electrical tester through the ECU which didn’t find any faults. The garage can’t find anything wrong and its starting to get dangerous as it cuts out on roundabouts. Any ideas?