I have an old '99 Volvo S70, which is notorious for NOT passing the Smog Test. As part of my 6 months service check, Adam did a test drive on the freeway. He told me the Smog Test problem had to do with the computer codes & something related to an "anti-theft" device on the car. Miraculously, whatever he did to "fix" the problem allowed me to pass the Smog Test on the first try. I have been taking my Volvo to Ackerman's for 18 years & always feel that I have received excellent service on my car.