infiniti qx4 won't start

car just stop running so i was told that i need catalytic converter. payed
$1500
for the 2 converters and drove the car for 5 miles and it stop running again
on the highway. I had it towed to a shop and i was told that i needed a new
distributor and it would be ok. T he car ran for 2 days and on my way home
from work the seem thing happened again, now it won't start. it tries to start
and when it do it cuts off like it's need getting any gas. Fuel pump is work
and filter is new and did a test to see if it was getting a spark and that's
good to, don't know what the problem is.