Seems like you and I have the same problem. I just had my oil gasket replaced, along with plugs and got my car back Thurs. On Friday I was at a stop light and I noticed the RPM go down from it's usual spot on idle. The car started shaking uncontrollably, especially from the front part of the car. The engine felt like giving out and the car turned off. Once I started it again, it had a rough start and Service Engine Soon light came on. Took it back to Indy to get it scanned and checked. Turns out my cam sensor is out. Supposedly there is oil build-up in the VANOS. I'm getting service done Monday, so I'll report back. That might be the problem for you, not sure though.