A week or so a go I managed to trip the engine warning light pissing about with the map sensor... I got a fault code of high voltage which was reset by Chiswick Honda... All I actually did was disconnect it give it a wipe and reconnect it.... all with the ignition off.. Not sure how that would trip that fault code.... Anyway I digress.

I still have the boggy sensation with wide open at around 2700rpm. I have not been back to Chiswick to get it sorted.... It

 

My K&N certainly had no affect on the Map Sensor. I'd leave the lid on TBH. Have you considered replacing the sensor - the newer ones have an integrated cable tie type clip which ensures that the sensor is tight.

Have you checked that none of the hoses have cracks in them.

 

K&N will be MAP friendly.

It's more likely to bugger up due to the oil mist coming from the crank case breather.

Lid on or off will not affect the MAP.

For hesitation advice there are some checks you can do in the link in my signature.

 

What link?

 

I think he means this one m1bjr?