Prius scheduled maintenance

My wife’s 2002 Prius is due a 55,000 mile maintenance. The service manager told her they need to clean the injectors and de-carbonize the pistons. I have been told that the gasoline has chemicals in it to keep the injectors clean, but I don’t know about the decarbonizing process. My thinking is that these procedures are meant to clean and decarbonize my wallet of about $160 bucks. Am I wrong,and do I need these things done?

That’s a complete load of crap. This is a sleazy dealer. Do NOT go back to this dealer EVER. Post the dealers name so everyone here can avoid this sleazler.

Your assumptions are correct. Find another place to do your maintenance.

This is completely unnecessary and nothing but a profit generator. Read the maintenance schedule that came with the owner’s manual. Your wife’s Prius only needs the specified maintenance. If you find fuel injection cleaning or piston de-carbonizing on the factory maintenance schedule I’ll pay for it.

You are correct about detergents in gasoline. They are required by law and all gasoline has them. Toyota is a manufacturer that recommends Top Tier Gas. You may want to check it out at

Am I wrong,and do I need these things done?

No you are right. Unless the manufacturer provides FREE maintenance, there is no reason you need to bring you car to a dealer. You have almost always save money and have equal or better service from an independent mechanic

Ask him to show you where they are listed in the manual. Didn’t think so!

De-carbonizing the pistons has not been necessary for very many years, thanks to the newer technologies, such as fuel injection and computerized engine controls.

Cleaning the injectors might be valid if the car is exhibiting specific symptoms of clogged injectors. Unless you have mentioned to the service department that your car has a rough idle, is bogging down upon acceleration, or has lost some of its original performance, this service is almost as bogus as the piston de-carbonizing.

As others have said, this dealership sounds like one to avoid.