The Nissan Path

Check engine light is on, however no communication with Snap On Versus Scan tool. Also, the engine is running extremely rich, resulting in both a high and low idle miss. Unplugged mass air flow sensor and the vehicle immediately shut off. TPS shows within parameters.

I'm really at a loss here, and if any of this looks like a familiar problem to any of you guys, any help would be extremely appreciated.

Thanks.

Mine shuts off also when I disconnect the air plenum pipes so I wouldn't worry about that. Have you tried an Autozone or Advance el-cheapo reader they let you use for free ? Key on but engine off

Check your fuses, first. You could try checking for codes using the mode screw on the ECM. You can find the procedure here:

http://www.troublecodes.net/Nissan/