I have just joined this forum so that I may be of assistance to those with rare difficult issues. I have been the Chief Senior Mechanic for the firm for nearly 15 years. I have multiple certifications, train many mechanics, and a total expert in Nissan vehicles. I have yet to run into an issue that I was not able to solve. Of course, it assumes I am given correct and full information. I have 6 certifications both from the company and from a number of Mechanic Associations. When Nissan engineers are stuck on an issue, I am frequently consulted.