Best spot we know of is Performance Dyno in New Hampshire. I know it's not very local but Pete has done a lot of cars from this area and nobody has ever had an issue. The last few springs we've had a run down to get cars tuned or just put on the dyno. I'm sure there might be a few next spring wanting to go. He's one of the best in the business in my opinion
If you want to keep it Canadian content, you absolutely can't go wrong with Mat Dasilva at Dasilva Racing in Pickering. Brock Rd., exit 399 off the 401. Very easy to find and get to. I agree with Ohtobbad, I'm not aware of anyone in the Maritimes that does that stuff. Your car will perform great and better driveability, while still safe. No codes and no damage to the car. This is link to their site: http://www.dasilvaracing.com/
I've known Joe and Mat for 8 years and been there several times with two cars. They are artists of their craft. They absolutely aim to please and won't let you leave unless you are satisfied with the work.