Unfortunately we did make an error and forgot to use the customer supplied oil as they requested. We apologized for the mistake and to make up for the error we changed the oil with customer supplied oil and provided free labor for installing spark plug wires.
We are up front with our customers on diagnostic charges for Check Engine lights and other components that may not be working. If we are able to diagnosis the problem/issue fairly quickly, we only charge half the diagnosis fee. Unfortunately, this customers' personal extended warranty did not cover diagnostic fees on three of the visits that required diagnostics for check engine light or non-operating parts (6 visits total in 2015).