Fuel Injection Cleaning -- Yay or Nay?


A shop has recommended that – in addition to the need to replace #3 ignition coil and spark plugs – the fuel injection system and throttle body should be cleaned. This recommendation, I was told, was because of accumulated dirt.

Over the years I have heard opposing ideas about such a cleaning … one says that it’s a “good thing to do” and the other says it is irrelevant and a waste of money.

So, wise community, I wonder what your opinion is?

2001 Lexus RX300

Clean the throttle body, yes. The fuel injectors should probably not need cleaning unless you’re noticing driveability problems or if you use poor quality fuel (small town gas stations). I would recommend cleaning the throttle body with throttle body cleaner that is available at parts stores and running Chevron Techron in the next tank or 2 of fuel. Unless you’re experiencing problems, doing those two things should be good enough.


If you use Top Tier gasoline, a fuel injection cleaning shouldn’t necessary. Especially if there’s no engine performance issues.

A throttle body cleaning might be needed given the age of the vehicle, and if you can’t remember if it’s ever been done.



If it’s running rough, the coil and plugs are where I’d start. See how it runs after that. The rest might just be added to pad the bill.


Thank you all; much appreciated.

Throttle body cleaning can certainly be needed considering the age of the car.

The problem with fuel injector cleaning is that cleaning solvents of any type will only affect varnish residue and so on. It will do nothing if the tiny fuel inector screens are partially clogged with micron sized debris or if the injector pintle and seat is badly worn.


I agree about the throttle body cleaning. However, I have never, ever, not once ever, needed to clean any injectors on any vehicle I have ever owned…and I have owned more than 100 vehicles in my day…as a mechanic I go thru cars and flip projects like its my job…oh wait…it is sorta my job! LOL

NAY on the injector cleaning…if you want to split the difference…buy a high quality injector cleaning additive and add it to a fresh tank o fuel…that’s all I would do if I just couldn’t get it off my mind. But otherwise another Nay from me and I bet your RX300 engine runs smooth as silk already.