Appreciate what Osborn's attempted to accomplish during this service when they attempted to correct a failed smog check on our 1991 truck. I did not understand that they are not equipped to do the testing, so it was hard for them to nail down the problem w/o that testing equipment. As it turned out, Osborn's replaced the OX sensor which did not help us pass the second smog test. Per their recommendation, they referred us to a Star Test and Repair station (Anza Mobile). They replaced the new OX sensor from Osborn's and the truck passed! Looks like the first OX sensor was faulty. No matter what, we trust Osborn's and recommend them to our family/friends.