If it wore through, then there is already damage to the fuel pump actuator rod, and the cam lobe. Sooner or later you will notice the car stumble at idle, like I did, sorta like when a coil starts to intermittantly fail. You might also notice, that the engine acts like it's cutting out at high speed in high gear when you are really hitting the throttle. Once my light came on, the car suddenly had no power at any rpm, and could barely maintain 55 and 70mph while floored, on gentle rolling grades. Like I mentioned in one of the other treads, the damage to my "06" was so bad that the fuel pump, intake cam, exhaust cam, and entire head had to be replaced. When the light came on, I quickly got home, and the next day got to the dealer. For some reason my light didn't trigger until the damage was catastrophic. On the way home I stopped at the auto parts store, and had the codes read, and was totally sick. The two codes that you don't want to see together popped up pointing the the follower. Thankfully everything was covered, and I got absolutely no grief from Audi, and at 108,500 miles, I essentially ended up with a totally new upper engine. I was actually seriously considering dumping the car right after 120,000 miles, if the failure hadn't happened by then, because the repairs would have cost about half the current value of my car if I had been stuck with the bill.