A collection of scopes

Diagnosing modern engines without an oscilloscopes really is a  waste of time
Here at lunar we have an ever growing collection.NO1 among them is without doubt the pico

Its all in the exhaust

Your exhaust seems to be nice constant stream,seems to be.In fact there are  rises and falls in that  apparently constant stream
How do you detect them?
You need a signal generator and an oscilloscope which can detect very short time periods,ie 2 milliseconds,it a great diagnostic tool without  even lifting the bonnet.