Can I improve my 2009 ac myself???

Refrigerant can be sold pure, or with various additives in it, like oil, with the idea of replacing some of the original oil that you think might have leaked out with the old refrigerant.

You can add absolutely pure refrigerant, or you can add refrigerant with oil if the oil is guaranteed safe for a hybrid's electric compressor.

If you add refrigerant with oil made for "a normal car", or even if you use hoses that have touched such oil, it will immediately begin degrading the insulation in the electric compressor. As soon as that insulation shorts across, your car's A/C will be done.

Refrigerant in an air conditioner doesn't have a 'level' to 'top off' to like engine 'coolant'. It is there in the system in both liquid and vapor form all the time. When the system is off, with anywhere even near the right amount, its pressure just tells you what the temperature is, not how much refrigerant is inside. When the system is on, the pressure behavior is complicated.

The refrigerant is best measured into the system by weight, but you don't know how much is left in there, so that should be safely recovered first, and then the proper amount put in by weight. That's the way a decent shop will do it (whether a dealer or any good independent car A/C shop).

@lech auto air conditionin can explain more about the likely results of the $40 parts store method.

 

Don’t know where your reading take it to the dealer but that’s the last place to take it at $180 an hour.
Prius is a very common car ac shops know about it.

Do not use the can you bought. G2 ac when working properly is freezing
If yours is not it has a slow leak. Take it to a good shop they will charge it up with dye and find the leak. Dont be surprised if it’s the ecoil under the dash very common on this car. They charge $150 by me for a charge and dye.

Just had my ecoil replaced on my 07 it is freaking freezing. Have to run it at 70 or it’s uncomfortable.

 

I have a 2009 with 190k and the ac works decent.

You have a normal 12 year old car. No automotive AC system is perfectly sealed and all will experience some amount of refrigerant leakage. A perfect seal will be invented right after a perpetual motion machine. Your statement (above) says it all. Normal degradation. Most likely all it needs is a 'tune up', not component replacement.

 

Interesting that there have been many 100°+ temps in Oregon over the last 100 years
Oregon Record High and Low Temperatures Interactive Map
I guess people were tougher then to survive without AC

 

Even more interesting to take the 45 "All Time Record High" dates from that map you linked, and put them in order.

Code:

1898-08-10
1905-07-08
1905-08-07
1922-07-02
1925-06-24
1928-07-23
1928-07-24
1939-08-23
1946-07-20
1946-07-20
1946-07-20
1955-09-04
1961-07-11
1961-07-11
1961-08-04
1961-08-04
1961-08-05
1977-08-18
1977-08-18
1979-09-14
1981-08-10
1981-08-10
1981-09-06
1990-07-12
1994-09-22
1998-08-05
2002-07-11
2002-07-12
2002-07-12
2002-07-13
2002-07-13
2003-07-23
2003-07-24
2009-07-29
2014-07-17
2018-08-10
2021-06-27
2021-06-28
2021-06-28
2021-06-28
2021-06-28
2021-06-29
2021-06-29
2021-06-30
2021-06-30

19 of them were set in the last 20 years, and 9 of those were set this year so far.

Maybe there's something going on besides Oregonians becoming wimps.

 

You can turn on the ac and look in the sight glass. It will probably look like condensation/ bubbles flowing fast through the glass which is not good.
Stop using the ac low charge is very hard on the compressor.

Like TMR says slow leak over years happens may be loose coupling or an easy fix. Mine leaked so slowly over years you hardly notice the decay in
Performance until it’s clearly not cooling well.

A proper working G2 ac system will freeze you out.

only way to tell is professional investigation. $150.

 

Some people get it right and some people do not.


your Prius should get this cold.