Skip the auto shop - Our mechanics make house calls

Q: Codes P0420 and P0171 appearing

asked by on

I took my car to the dealership to have it checked out. Two codes were found: PO420 and PO171. They told me that the P0420 is a problem with the actuator (part number 17230-21010), and the 2nd one has to do with the Mass Air Flow (22204-21010). Both of these makes my check engine light continually appear and they told me those codes are the reasons that my gas mileage becomes so low (33 mpg on average). The dealer suggested both be replaced. But then, when I brought the car back, the check engine light went “off.”

I also have a problem with the A/C: sometimes it cools and sometimes it doesn’t. The fan is on, but not the A/C. The mechanic says there’s no code for that and they say it’s the compressor (part number 88310-47030-84) and the Expansion Valve (88515-47020). They want to replace those too. Is there anyway I can get these type of problems repaired/replaced by some place other than the dealership or are these problems ‘only’ solvable by the Toyota dealership?"

A: When it relates to the air conditioning sys...

When it relates to the air conditioning system, the dealership does not have an advantage when it comes to hybrid air conditioning systems. These air conditioning systems require special evacuation machines that are different from that of a normal air conditioning system to remove the refrigerant from the system. Due to the high cost and low use of such a machine, most independent repair shops and mechanics do not have such tools to do such services. If you know someone who does have one of these machines and is willing to help you, you are certainly able to go that route unless for any reason it would void a warranty you may have on the vehicle.

As for the Check Engine Light codes, this sort of thing can be looked at and repaired almost anywhere. You do not have to go to the dealership for this. YourMechanic offers mobile mechanics who can inspect your car and thoroughly diagnose your Check Engine Lights, as well as any other issues your car is having, so that the correct repairs can be made.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: truck won't run at hight mph

Hello. The rear tire change would not have anything to do with the operation of the catalytic converter. There is however a possibility that when the catalytic converter codes came up that this triggered other issues as a result of...

Q: Bad O2 sensor

Hello, code P0420 represents right main catalyst deterioration. There can be a few things that need to be checked before replacing parts. The intake system needs to be inspected for vacuum leaks and unmetered air leaks. The exhaust system should...

Q: Driver's side noise on a Subaru

I imagine it would be. The thing about Subarus is that they are pretty small tolerance engines. The box design of Volkswagen and Porsche, it's kind of a dinosaur design but it puts out a reasonable amount of power. Start...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.