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Mercedes-Benz C-Class: How to Clean MAF Sensor and Throttle Body

The MAF sensor in your car dictates a lot of important things about your car's behavior, so it's best that it works properly. Here is how to clean the MAF sensor and throttle body in your Mercedes-Benz w204.

By Jerry Perez - June 8, 2015

This article applies to the Mercedes-Benz C-Class w204 (2007-2014).

The MAF or mass air flow sensor in your Mercedes-Benz plays a very important role in your car's performance. You can think of it as the one piece that dictates how much air and fuel is mixed before it goes into your engine to help you generate power. The richer the air and fuel mixture is, the more power your car will generate. But, on the other hand, if the mixture is too rich or too poor due to the sensor being clogged or damaged, then the mixture will be off. That can have some serious side effects in the driving dynamics of your vehicle. But before you replace the MAF sensor, you may want to try cleaning it to see if that solves the problem. This is also good preventive maintenance. If you are not familiar with these terms, you can also visit a repair shop for this job.

Materials Needed

  • Flat head screwdriver
  • MAF sensor cleaner
  • Throttle body cleaner
  • Rag

Step 1 – Disconnect battery

Before you begin any work with sensors or electrical components, always make sure to disconnect the battery to avoid any risk of shock as well as damaging any electrical components. Always disconnect the negative (black) terminal first, and then followed by the positive (red) terminal.

Figure 1. Make sure to disconnect the negative (black) terminal first.

Step 2 – Clean MAF sensor

First you must locate the MAF sensor, and then carefully un-clip it. It looks like a wiring connector just like many of them found in the engine compartment. Sometimes, you can use a flat head screwdriver to pop the clip out of place if it's hard. Once the sensor is out, use an appropriate MAF sensor cleaner and spray it around the sensor a few times. The spray will evaporate quickly, but make sure to give it time to dry if it builds up on the sensor.

  • Figure 2. MAF sensor location.
  • Figure 3. MAF sensor cleaner.

Step 3 – Remove intake tube

Now it's time to clean the intake throttle body, but to gain access to it, you must remove the plastic tube or elbow that the MAF sensor plugs into. This does not require any tools. Just make sure to carefully wiggle it out of place without hitting or damaging any other components.

Figure 4. Remove plastic elbow.

Step 4 – Clean throttle body

With the throttle body exposed, use an approved throttle body cleaner and spray it in the throttle body cavity, thoroughly. Make sure to place a rag surrounding the throttle body to make sure that any excess cleaner gets absorbed, and doesn't spread out through the engine block. Once you are done spraying, wait a few minutes to make sure the cleaner dries.

Figure 5. Throughly spray cleaner in the throttle body.

Step 5 – Finish up

From this point on, everything reattaches in exact reverse order as just performed. Follow these steps:

  • Attach the plastic tube to the throttle body.
  • Plug in the MAF sensor.
  • Reattach the plastic engine cover (if originally removed).
  • Finally, reconnect the battery.

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