Stalling while driving

Was there any abnormalities in engine performance etc prior to it stalling?

Dose it stall only when slowing down or even while cruising?

Does the dash indictor lights turn on when it stalled?

Sorry for the delay in replying. Since the upgrade our system is not yet back to normal yet so some delays could not be avoided.

Since the stalling occurs only when gas pedal is released and at slow speed, it most likely is an idling system fault.

When cold the fast idle would be in operation so the idling speed is increased. After warming the idling speed would drop and if the idle air intakes ia partially clogged, the idling speed would be lower than expected resulting in stalling at times.

Get the throttle body and Auxilary Air Control Valve (AACV or commonly known as IAC )cleaned and retest.

Get a can of carb cleaner.
Remove the air cleaner hose.

Spray carb cleaner into the throttle body.
Use a tooth brush to clean the interior of the throttle body with throttle plate fully opened.
Repeat till the interior is clean.

Disconnect the AACV from the intake manifold.
Use carb cleaner to clean the interior passages of the AACV.
Reinstall and restart enginew after installing all components.

Engine might be difficult and struggle to start due to the presence of carb cleaner and might even stall. Let engine run for a while with a little accelerator pressure until it stabilises and there could be excessive smoke from exhaust as well.

If the MIL is indicating, get a scan done to retrieve the trouble codes.

You should have more problems on hand. The difficult starting when cold could be due to a problem with the fuel pressure. Get the fuel pressure checked and perform a leak down test if pressure test is good.

Clean the MAF and also those as described in previous post.

The erratic shifting could be due to a bad throttle position sensor or transmission related faults. If the speedometer reading is erratic, it would cause transmission shifting fault as well.