is it possible to have a faulty map sensor without showing a error code

i have been getting what feels like a major flat spot blip the throttle and i get a pop from under the bonnet and shes sweet again

been told by my mapper its probably the map sensor but no codes

 

Yes it certainly is.
Due to the 'wide' margins of error the ECU works within, and it's capability to learn 'on the fly' it is possible for any of the sensors to be below 100% and not see a CEL.

 

thanks i have ordered one of matty so will test it and see

hopefully sort it out

cant uderstand what the popping noise is though