Hello from Adam in NYC
I have the NAS 4.0 and went thru quite a bit to get me to work fine. I changed the MAF (without needing to), changed the 02 sensors, then the shop that originally worked on the oxygens sensors destroyed the circuitry that read the oxygen sensors. Went thru four ECUs until I found one that worked with my truck (went to the dealer twice for the security wipe).
The symptoms sound like you are in limp mode. Get a cheap codereader (umm, I think you are OBD 1 since the 96 is OBD 2). Read the codes and start on your merry way (NOT!).
If you want to get rid of the o2 sensors, there are plenty of fooler sensors on eBay that would trick the ECU into thinking your emmissions are okay.
http://search.ebay.com/oxygen-sensor...sPageNameZWLRS
Adam in NYC
