I have an'01 Duramax with 75,000 miles. It started running a little rough andsurging plus was putting a lot of white smoke out at idle and smelled really strong of fuel. The dealer said would replace the 8 fuel injectors under the 6/200,000 extended warranty GM provided, but it also needed a fuel pressure regulator that was going to cost me $850. Does this sound right? It makes me nervous when two problems arise at the same time. Has anybody else had this problem and at what mileage? Thanks for your input.