Try this out! I had a similar problem and traced it to the ("radio suppression relay") This is attached to a bracket on the ignition coil above the passenger front wheel. This thing kills the ignition during decel to stop radio noise. Also check the wires going to it. They are most likely loosing insulation and should be replaced. Another thing to check are the grounds for the ecm that is behind the passenger's kick panel. Make sure the metal under the screw is clean and that the screw is tight. Good luck!