According to MFR Technical Service Bulletins, the most likely case of the Transmission jerk is a faulty
MAF sensor, i.e. entire vacuum system as well as the MAF.
A MAF fault may or may not be strong enough to trigger a DTC but If you do have a check engine light present, run down to the nearest Auto Parts store and ask for an associate to read and print out your trouble codes. Again, according to the MFR, harsh shifting may also be a symptom of:
Torque Converter Clutch (DTC 628 or P0741)
Transmission over temp (DTC 657 or P1783)
Trans Turbine Shaft Speed Sensor (check ohmic values)
Catalytic Issue?
A sulfur smell along with a stall issue is caused by Electronic engine control V, or the Powertrain control module and/or the HEGO sensors. For stall - reprogram PCM.
For stall and smell - replace both HEGO sensors.
No Trouble codes/No check engine light?
In my experience, cleaning the throttle body (especially the small hole near the butterfly valve's resting edge) with carb cleaner, and securing all vacuum leaks is a good first step, Next checkout the EGR system, the EGR valve may be sticking open for a few seconds. Use an inkjet refill syringe connected to the EGR valve via vacuum hose. Pull a quick vacuum. Engine should stumble and then recover quickly when vacuum is relieved. Delayed reactions indicate carbon buildup.
Another quick and cheap check --
Idle air control valve:
turn off engine, disconnect IAC, restart. If no change in rpm at idle, IAC is likely to be faulty
Use an ohm meter to check the solenoid by attaching the positive lead to the VPWR (vehicle power pin) and the negative lead to the IAC pin. Your resistance reading should be between 7.0 ohms and 13.0 ohms. If your reading is off, your IAC solenoid is bad.
Hope this helps,
-K
MAF Sensor TSB:
http://www.revbase.com/BBBMotor/TSb/DownloadPdf?id=44679
Ohmic values for Trans speed sensors:
http://www.revbase.com/BBBMotor/TSb/DownloadPdf?id=114945