I have the same wrench with a ratchet. I've owned it for about 5 years. Mine is also within 2% as are the other 3 Proto torque wrenches I have. No issues with any of them. You can send them in to Proto and they will calibrate and repair them very inexpensively.
I have one I bought on ebay for 50 bucks, without the end plug or a case. Sent it in for calibration. They called a few days later and said they would put a used end plug in for free, or a few dollars for a new one, calibration was fine. I went used and when I got it back a week later, it was in a like new case that had a few grease smudges. No charge for that either. Total cost $15.