do you recone my ECU is dying

[megabob]

Hi
ive had a new engine put in my VTR mk1 from a VTR mk2 grey top engine is in very good condition and has only done 38k, about a month ago i started having poor idling and car would sometimes stall at junctions, the ecu was checked and errors were coming up from the Lambda sensor i was also advised that i might need a new Idle actuator valve. i replaced the lambda and it was ok for about a week then the same problems arrived again so i got a new Idle actuator valve and fitted that but it made no difference and now the car is back to its old tricks again. Because of the issues ive been having the garage didn’t charge me to have a look this time but when they tried to access the ECU it refused to produce a diagnostic reading. the car will still start but the ECU will not give out a decent reading.
sounds like a dying ECU what do you think?

sorry for spelling reckon wrong was in a bit of a hurry