Just picked up my car from Volvo service. The CEL was on 2-4 days and off 2-4 days for about five months, beginning about a month or so after getting the beta fix for s-s-s. This was the second CEL episode. About a year ago, they replaced all five injectors and that took care of the CEL (I was getting misfire codes). The car always ran fine after a slightly rough warmup during both CEL periods. This time, after checking codes, doing a cylinder leakage test and a compression test (no faults found), they cleaned the intake system, valves and ports. Told me they had to decarb. I was shocked. Only 12,750 miles. They explained that the problem was the crappy gas we get in Oregon. Doesn't burn fully or cleanly and leaves some sort of residue. They suggested staying away from premium grade gas, which is the biggest problem. This was a warranty claim which otherwise would have been $500-$600. I have no confidence that it won't happen again. Volvo is blaming the gas and said other manufacturers are having similar problems, but it seems to me that they didn't properly test the cars against US gas. I would love to get a reaction from someone who knows a lot more about this stuff than me.