2010 Prius IV - 150k maintenance, mpg downfall

My Prius 2010 IV was giving me 50mpg when I drive 72-85mph without patient driving (I never tried so never know the true top mpg).

2020, i was out of country and got stuck due to international travel ban.
From Mar 2020-Feb 2021, the car wasnt driven, stored in a friends space.

For some reason he decided to give the car to college kids in Chicago (drove 200miles from Michigan) after changing the oil. By that time, from records i see the Toyota showroom showed 0 on RR wheel brakepad meaning it HAD to be changed. I am not sure if he decided to ignore or never got a verbal communication when he got the oil service, but after he gave car to them, those college kids drove about a month 400miles, to the extent that brake pads completely gone, pistons gone, Boosters stuck and brake fluid leaked all over. They towed to dealership and they gave them a bill above 2k to fix. Thats when that friend called me (first time i am hearing car is not in Mi and been drove by kids) to say car is broke and if i want it to be fixed (obviously asked me for money to fix it as it is beyond their pocket money). I asked them to just keep the car stored until I return as i was in hell lot of stress after losing my father on Kidney failure and big bills paid.

I came to Michigan on June, got help from my local mechanic contacts, towed the car from Chicago to Michigan (I couldn't travel with a 2yo kid on home and other friends are busy to drive it back).

He worked on the car, changed both rotor on back wheels, changed calipers, said boosters are fine but he got them worked out and he said it was difficult to get the brake fluid straight as air went in the lines and he had to spend more than 2gal to get it fixed. He said the front wheel rotor may also need to be replaced in near future, advised me to replace them if i am taking the car for any long rides or having trouble in braking.

Now the current issues
1. Car brake maintenance lights (ABS, brake, anti skid) come 4/10 rides and sometimes stay or goes off
2. From 50mpg it went to 36mpg
3. Wife doesn't want to drive it, as she says, brake to be on lower end. For me it is low, but not lower. Not sure if it is because of the front rotor that mechanic asked to change

I bought a OBD checker from Amazon and it showed below two issues. I am taking the car to the mechanic
Car Scanner ELM OBD2
DTC report
Selected brand: Toyota
============1==============
C1202
Raw code: 5202
ECU: ABS control unit #2
Status: Confirmed

============2==============
U0155
Raw code: C155
ECU: Entry & start / Smart key
Status: Confirmed
OBDII: Data bus, instrumentation control module - no communication


I am planning to keep the car for long run, want to fix all issues. If we need to upgrade, wife in past said to sell the Camry hybrid (we like 35-40mpg, comfort, ride on Camry, but in trunk space, Prius beat it).

The mechanic is good, I am working with him last 6 years, no complaints. But he is not specialist on hybrids. Car is at 139K miles and showroom may want to push me for doing 150k maintenance (I dont know if they push me for all kind of fluid flush) and ask me a big bill.

I am not good at car mechanics. In this scenario, what is the best thing i should be doing?

 

I took it to the mechanic, he ran and confirmed the C1202 code. But to him the brake mechanics sound good. He is thinking two scenarios
1. switch might have gone bad or 2. Module needs to reprogram (which of case, he said only dealer could reprogram)

Unfortunately his garage going under renovation, he asked me to wait 2 weeks before dropping it. But to him, car sounds mechanically good, he tried clearing the codes but it came back. He says its safe to drive though codes appear may be faulty switch.

I am going to take it to dealer to check, hopefully they don't ask me big bucks just to run diagnostics.

 

I know, its crazy. Accident, getting stolen or speeding ticket, can't think any to add our rough times.

Gracefully I had to only deal with loss of money for tow, repair the car. At times losing money is way better than dealing with other issue.

 

Thanks. I will try that. I have to get the car to a friend house.
Local mechanic suspected two things. 1. Bad filters (he dusted the engine filter, asked me to buy, change new one as its 2+ year old) 2. Asked me to use Premium gas for two full tanks. When I asked him about bad brake or wheel alignment position, he said he tested them when he changed rotors and all checked fine l. But he does believe the mileage shouldn't drop this much.

 

Not as same before.

 

I guess it is. He said if there is some issues for to car not ran for morethan a year, sometimes Premium would help solving by its own. I don't know what he meant by that.

Do dealership charge for diagnostics? If there is some 150k maintenance, worth to do that now?