NORWALK - The Connecticut Department of Motor Vehicles will be mailing out late fees for overdue emissions testing this week following unprecedented computer problems.

Starting Thursday, the DMV says more than 200,000 notices will be sent out to collect a backlog of $4 million in uncollected fees dating to last August. That's when the department shut down its computerized registration system in preparation of switching over to its newly upgraded, $26 million system. The computer glitch delayed late fee notices from going out.

The DMV says motorists can renew their registration if they have a late fee, but it has not been determined how long that grace period will last. The late fee is $20 on top of the $20 emissions charge.

The department says it wanted to make sure it handled the process correctly.

Anyone who thinks they might owe an emissions test late fee can check the DMV's website.