I have a 2004 mercedes c240 and have a new crank censor to install. Where is the censors location on the 6 cylinder?

Check coolant level . leaking fuel lines while running and stopped, gas tank filler cap , temperature censor ,low oil pressure , crank censor and fuel pump . Could also be the ECU ...

Google a picture

Hope you not throwing parts at it,
without doing any testing, to find a
problem or failed part

That could get time consuming & costly
& fix nothing

Codes don't tell you to replace parts

Prove me wrong once, if you like

Then the next ten years it will bite you

Have to learn how things work & how to test them

it might be this sensor I can't think of the name of it but it is located by the thermostat. it is held on with 2 10mm bolts and has a connector similar to the mass sensor on it. This sensor controls spark.

Run the fault codes as what you have done may only be by passing the real faulty sensor. Check the cat converter for failure and blocking the exhaust system

Should have four, one in front and one after each catalytic converter.

crankshaft position sensor is located on the transmission bell housing on the left side/ driver side of the engine. It reads off the flywheel. You probably have to feel for it because they are hard to see from the top side.

Crank sensor is right behind your harmonic balancer (3 or 4 pin connector). You cam sensor is in your distributor under your rotor...

brake booster check valve leaking.

Hi, You need to replace the alarm siren. It is also a module. It is located in the right front fender well. The reason they go bad is because they are located in a place where they get wet.