Nissan Repair: Nissan 2000 Xterra XE -acceleration/engine probs, nissan xterra, air meter

Question
I've now had my 2000 Nissan Xterra (115k miles and just fine til latley)
looked at by 2 mechanics and neither one can address why the engine will
seize up and eventually stall. No overheating, just starts chugging, spitting,
then craps out. I've had a new distributor, dist cap, tune up, what seems like
the works done, but within 2-3 days after leaving shop, the problem returns.
Help...is this the KNOCK SENSOR, as one mechanic might think? I can't afford
to keep this up much longer not to mention stalling on the interstate, etc.
Appreciate any insight you might have and Thank you.

Answer
Craig,

I would not spend another dime until the mechanics can tell you the fuel pressure is normal and there are no codes.  That is, the knock sensor should throw a code.  I would not replace it unless it shows a code.  Most probably the air meter would be the problem if the fuel pressure is normal.  Have them throw the Xterra on the computer and verify that there are no codes.  That includes pending codes.  Those are ones that do not set the check engine light.