1998 Honda Civic exhaust system problems

I began the process of having the car repaired on august 14, 2000. By today, august 18th, the honda dealer had mentioned to the repair shop that iam having the work done at that they had ordered 6 of these manifolds. On monday when I had called the dealer for parts, they did not have the manifold in stock. I belive that this could be a sign of a major defect. Although it does not directly pose a threat to me physically, it could allow exhuaust fumes into the vehicle.

1998 honda crv, with about 100,000 milage,engine light came on. Repaired the distributor sensor. Took it back four more times and the engine light continue to stay on. A week later, took it in to deale for a diagnostic, valve #3 & 4, needed to be replaced, they recommended a new cylinder head. Notified honda manufacturer and they decided to pay half of the cost. I have always taken good care of my car, and have the invoices to proof it.