A Secure Torx bit set can be purchased online and is inexpensive. Make sure to get a set of secure torx bits. If cleaning does not fix the problem, replace the MAF sensor.Avoid touching the sensor with an object. Spray MAF sensor cleaner on the plate inside.Mechanics or the dealer are unlikely to perform the cleaning procedure so you will have to try this yourself. You will need MAF Sensor Cleaner to spray on the sensor. First, clean the Mass Air Flow (MAF) sensor.Always clean or replace the MAF sensor first. These items are unlikely to fix the P0170/P0173 codes. Common misdiagnosis includes bad Oxygen sensors or worn spark plugs. In fact, these two codes are often misdiagnosed.

If you troubleshoot this issue based on the two codes, a mechanic can misdiagnose the problem. Fuel Supply Issue. If you have issues during a cold start, it is more likely a fuel related issue.Vacum leaks near the o-ring of the fuel injectors.Replacing the MAF sensor is easy and can be found here. Replacing the MAF sensor yourself will cost you under $100.

Replacing the MAF sensor at the dealer can cost between $350-$500. If you are using an air filter such as K&N, you may be contributing to this problem because these filters allow larger particles to pass and also have oil that can coat the MAF sensor. The MAF sensor gets dirty over time triggering the CEL and the two codes.

The most common cause of P0170 and P0173 on a Mercedes-Benz is a defective mass-airflow sensor.

Under certain circumstances such as vacuum leaks, the car may run fine even if the CEL light is on and P0173/P0170 are present.

CEL may come on for a few day, then turns off.

If you clear the P0170 and P0173 without fixing the underlying problem those two codes will return in a couple of days. Other codes that you may get are P0130, P0135. This issue can affect any Mercedes-Benz model including C, E, S, ML, GL, CLK, GLK, SLK, GLE classes. These codes can be misleading because if a mechanic goes by the book he may not suspect the problem to be the MAF sensor. If the codes remain it is possible you have a vacuum leak. You can try cleaning the sensor but that doesn’t always work. Most of the time these Mercedes-Benz fault codes are caused by a defective Mercedes Mass Air Flow Sensor (MAF) sensor. In theory, these two codes mean that the fuel mixture is too rich or too lean. Mercedes-Benz owners may notice the check engine light plus P0170 and P0173 codes.

Sprinter mass air flow sensor problems