I went to have an emissions test done on my 2013 Kenworth equipped with a MX-13 Paccar engine. They got my truck in very quickly. However, at the conclusion of my vehicles test an office employee told me that the test was complete and my vehicle failed due to a check engine light that came on during the test. I was told if I wanted to find out why the check engine light came on I would have to pay an additional $138 for the technician to plug in and read the code. After paying them $100 (for the failed test only) and leaving there facility (frustrated) I could NOT get my check engine light to illuminate during any road test that I performed and promptly return to confront Springs Auto about the issue that they found while testing. They told me that my truck passed the emissions portion of the test but failed due the check engine light coming on while performing the test. As soon as the vehicle ignition was turned off the check engine light would go off and would NOT return. After doing much research on how this could happen (seeing how my check engine light has NEVER come on before ) I decided to take my truck to Exhaust Readers on N . Nevada. They got me in very quickly and performed the same test. My vehicle passed!!! Their tech told me that the reason for the check engine light (during the test) was because the ABS sensor detected that one axle was rotating while the other axle was not which will cause a ABS fault in the ECU and in turn will cause the check engine light to illuminate. This can easily be confirmed by plugging into the ECU and reading the check engine light code(which was NO ADDITIONAL CHARGE at Exhaust Readers)! I was relieved and happy to pay Exhaust Readers $80 as opposed to $100 and a free copy of the Paccar/ Kenworth statement of fact provided by Kenworth and the state of Colorado explaining why the check engine will illuminate during an emissions test. Many costly things could have been avoided if Springs Auto would have been better educated and updated on how to correctly performed emissions test. My advice, don’t waste your time with a company that is still learning. Take it to a professional like Exhaust Readers. It will save you time and money!