How to Clean the Throttle Body
2004-2009 Toyota Prius
This is another simple maintenance item that often gets overlooked but it's important because the throttle body controls how much air enters the ICE. If this part is too built up with gunk you get decreased performance, can experience engine stalls or even no starting. The Prius makes this job real easy and you don't need to remove many parts.
- Toothbrush (yep, it works well)
- Metal rod or long screwdriver
1) Remove the engine air filter and MAF, prep work area as shown. Now some folks do this without removing the MAF. My personal opinion is that it's easier to clean without having that sensor in the way. Plus, I don't want to worry about getting throttle cleaner on an expensive sensor and it only adds a few minutes to the job.
Looking down you can see the clean side of the throttle plate (brass). For reference the red arrow points to the location you need to put your hand to turn the spring for the throttle plate.
Circled in red is the spring for the throttle plate.
Highlighted in green is a tab where you can rest your finger and rotate counter-clockwise to open the throttle plate so it can be cleaned.
2) Rotate the spring and use your other hand to clean the dirty side of the throttle plate and throttle body walls with throttle body cleaner. Spray areas with liberal amounts and use the toothbrush to scrub the debris off. Remember that what goes in there must be burned off by the engine. After a spray and scrub I used a few shop towels duct taped to the end of a long screwdriver to clean off the residue as you can see in the pic. Basically, this throttle plate needs to be able to rotate freely so you don't want any build up / obstructions. The goal is to only see metal on the plate and walls of the throttle body.
- Cleaning Throttle Bodies by Popular Mechanics
- Completely stuck throttle plate cleaning tutorial by Bob Wilson
- Complete throttle body disassembly & cleaning by Hobbit
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