Do you think it could be poor fuel injection? Maybe the sprays are off?
I was fortunate today...drove it 350 miles from Wash. DC to NY with no problems, despite being stuck in stop and go traffic.
The dealer told me they changed the oil and the filter, so it has been flushed; in fact, they changed the oil right before labor day too so that's 2 times in about 5 weeks. Oddly enough my horn went today too, so perhaps there are coroded electrical connections somewhere in the circuitry. It's just so frustrating and really mind boggling that they couldn't pull any codes.