You say the error code goes away on the dash, fire up your esl and see if the fault code is still logged when it scans, if it is, clear it and see what occurs

If i clear it on the scan, it doesnt free up the boost straight away. I still have to reset my ECU (unplug battery overnight) before the original boost map is back.

And then its just x weeks/days/minutes before the CEL comes back on again. Either whilst idling in the driveway, sat doing 30mph, or not at all even after a long hard blast. There's defo something f*cked up with the circuit as even when sat on the driveway with ignition off I had cyclic knock count rising loads! Then the next time i took it out the CEL didnt even come on at all!

Alyn suggested what i had forgotten about for a while - could be a loose ground somewhere. The shielded wiring to the sensor is baffling (for me anyway) so could be something along that route. Im just gonna leave it at AS Performance (hopefully if i can get it booked in in September) and tell them to just sort it however!

I'd rather they came back to me saying nah your engine is f*cked than come back saying they have no idea! Its not the money that bothers me its the amount of time and effort i've spent trying to get this car ready and its had this problem from the start and still cant find the remedy...

Yeah by the fault flagging up its probably lowering the IAM so even clearing the code via esl will keep you with an IAM of 0 for example, thus having to reset ecu to put it back to the reset value usually 8.

If it were me, id set my IAM reset value to 16 clear the code and reset the ecu by key in ignition but off, foot to the floor on the throttle , turn key to on and reset this way, much quicker.
You do have to check which map it goes onto though as esl has 2 maps, so make sure either both maps have the same IAM value and boost settings or repeat the reset method via ignition until the check engine light flashes 1 or 2 times to the desired map you want

Then that way it gives you an instant IAM of 16 so can test the car quic ker than letting the car learn

Aye exactly . Yeh good point. Will put that in for the next month. Should speed up resets (Y)

Very helpful guy is Alyn,I would be looking at the grounds,all the sensors run to the same block/pin,you might spot a broken wire.
I honestly wish I could help out more mate,I'm just so busy,not even had time to dial in my bcs and my car is a lag monster atm,I have cured the overboost tho :)

Also have you switched knock control off yet and tried running?

I havent actually changed anything yet. I dont have a laptop and my brother has moved away! I'm buying a laptop very soon though so will be getting ESL on it ASAP.

The car's actually been fine since last reset over a week ago... but i know the problem is there still and sure enough the CEL will come on eventually.

I hope Alyn will be able to replicate it, and subsequently diagnose / fix it.

**

Got a guy coming to do the windscreen on Friday, will be nice to not have a damp musty smelling car for the first time in 6 months :D

Id also disconnect the knock sensor and see if it replicates the fault when driving etc