need some help... 99 tahoe 150+ miles. Starting hesitating, almost like a misfire about 2 mo ago. It would only do it for about the first ten - 20 minutes of drive time after that it would run fine. Once it would reach optimal temp it was fine. Them one morning it would start. Acted like it was out of time, I thought the cat's were stopped up. Had them cut. O2 Sensor still there. It was done right...Drove fine for a couple of days then same thing occured started hesitating again. Sputtering almost. Read a bunch of forums and came to the conclusion of changing the fuel pump. Same thing, sputtering. The next day I changed the FPR. Same thing. Ok. took it and had the codes pulled. So many I couldn't narow my search. Three different codes showed a misfire in three diferent cylinders. We cleared the codes and it ran fine for about thre or four days. It started it again. Not it won't even start. It will turn over. It will act like it will almost start but won't catch. Changed the Mass Air Flow Sensor and plugs today and still nothing. Any ideas? Any guesses? Anything? I'm going to check the codes tomottor and see if I can pinpoint anything close.