I took my Ford Explorer in Sat July 19 because the check engine light had come on during the week. They found that the 4th Cylinder was misfiring and fixed it with a new coil and full overhaul on the spark plugs and wires. The next day I went 20 miles and the light came back on.....I took it back on Monday, July 20th and they found that another piece had been cracked causing a vacuum. They fixed it under warrantee and did not charge for the engine scan, part, or labor. They were really dedicated to make sure the customer was happy and that they fixed the issue even though it took more than one attempt. That is all we can ask for.