For the lock problem, go to your dealer and ask them to cut a key for you using the VIN. They may ask you to show proof of ownership.

I don’t know anything about the gauges sold by harbor freight. They’re probably ok. Certainly better than the gauges on the Freon cans.

 

For the AC system, are you using the correct port? There are two of them. One is the high pressure port, the other is the low pressure port. You need to use the low pressure port. Could you post a picture of the port you are trying to use to recharge the system (with the cap on in one photo, off in a second photo)?

For the door lock cylinders, the cylinders are opposite hand type, so they are different between the right hand vs. left hand sides (see the parts diagram below). I would almost think the key would wear out before the cylinders would. Maybe the LH cylinder has a bit more wear than the RH cylinder, but if the key is also worn, that could be your issue. If you have the key code (typically provided and found in the owners manual), have the dealership make a new master key and see if that will make any difference. Yes, the cylinders with the key cost about $78.00 each, and you would have a unique key on the LH side if you went this route. I would think the labor would be far more expensive to make the change. Plus the LH cylinder would need to be modified by the dealer to fit your master key (if you wanted all your locks to remain keyed the same). Also, the LH Door Lock Cylinder & Key Set (P/N 69052-41010) is only used on Avalon models from 1995-1999 (not interchangeable with Tacoma's). Hope this helps you.

 

The connector is not fully inserted: some connectors require you to pull the locking ring upwards at the same time as pushing the center of the connector