does a new ETM need to be calibrated at a volvo dealership?

What is your question?

my 2006 v70 turbo sputters at idle and gas mileage is poor. my research indicate that the ETM needs to cleaned or replaced. engine has 200,000. i can get bosch OEM on Ebay for $125, including casket. i called Volvo to check on part number and was "warned" that if i put a new ETM on, then it will not run right unless a Volvo dealer does a computer upgrade to calibrate the new ETM. this sounds like BS to me and just another way for Volvo dealer to suck my $$$. i already replaced the mass air flow sensor. no change. check engine lite goes on for awhile, then goes off. would appreciate your advice.

What makes this problem better or worse?

it comes and goes in all weather conditions.

How long has your 2006 Volvo V70 had this problem?

off and on for a year or so