Hello....I'm new to the group so bare with me. I purchased an 02 Millennia today as a cash car gift to my son. Took it to get codes and I have 2. P0750 and P1743. Any suggestions on where to begin? Anything will be helpful.

 

Welcome to the forum

 

The concern may be in the transmission that may not have ever been serviced. If you have a record of servicing, it helps. Otherwise, be prepared for less than the best findings. You could pull a sample of the fluid though the transmission dipstick area and send it in. Or perhaps the better advise just take your Mazda to a specialized service shops that deal specifically in automatic transmissions?

To normally confirm any DTC(s) for DIY this is generally the way to do it.
You first need a good grade diagnostic tool that will connect directly to the OBDII diagnostic connector. NO BLUE TOOTH TOOLS!
Then go into the file and check for all DTCs. If those 2 are still there note them.
Then go to the monitors and check for state of readiness or if the complete emission system is in state of readiness or no fault/ Generally it should read all green on most scanners.
then you will want to clear all DTC including pending DTC and reset the monitors.
When the car has sat for about 12 hours you can start a new engine cycle with your cleared ECU data. As soon as you get a check engine light pull over and retrieve the DTC and note it. At that end of your normal driving day recheck all the first part of this procedure.
Post you results and will see where a plan of action should go for curing your DTC(s).