What does codes po442,po442pd and po742 mean - 1999 Chevrolet Lumina

That is an emissions code. It means you have a small leak in one of the lines. Most likely it the line that goes from the engine to the evap canister in the drivers side rear inner fender well.

Yes, it is a Transmission code: PO742 Torque Converter Clutch Circuit Stuck On

Here's a link to your P0442 code.

Yes in most cases the torque converter is defective, you will need to have the transmission removed to replace the torque converter.

P0442 code means that the control module has detected a small leak in the Evaporative Emission (EVAP). The loose fuel tank filler cap is the most common cause that triggers the P0442 code.

Code P0445 indicates that there is improper purge flow in the EVAP system caused by a shorted purge valve.

Make sure Fuel tank cap is tightened well, then have it tested at Autozone, etc... If ok, then go back to inspection station.

this is a evaporative emissions code. which means there is a leak in the piping or something leading to the gasoline tank that is allowing fuel vapors to escape. More often than not the gas cap isn't tight or needs to be replaced. try these first

code PO742 means torque converter clutch circuit stuck in on position

Most of the time they mean:
p0441 = Evaporative Emission System Incorrect Purge Flow
p0422 = Evaporative Emission Control System Leak Detected (small leak)

MOre info at http://www.obd-codes.com/p0442

"Torque converter clutch" solenoid is stuck open which is causing your bucking problems. The solenoid is either disconnected or faulty. if you ran over something, it may have damaged the wiring, but if not, you need to take it in for checkup.

evap emission control system fault-po441, po742 is--torque converter curcuit stuck on, for this code, check torque converter clutch switch..