P0101 MAF sensor -clean it with an approved cleaner
P0300 Random misfires normally caused by vacuum leaks and bad fuel
Check the fuel pressure with a manual gauge. See what happens when you shut the vehicle off. I have seen these SFI engines develop leaks in the fuel lines under the upper intake and shoot raw fuel into one side of the engine. The computer freaks out when it sees the unburnt fuel and tries to compensate. As strange as it sounds raw fuel can create a false lean due to the fact the oxygen is present due to the lack of combustion. Thus a "Lean" mixture. A blown fuel pressure regulator can do the same thing
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Sunday, May 30th, 2010 AT 6:58 PM