p0172 code on m111 c230k

[famasfilms]

I purchased a 2002 c230k coupe in February, 70k miles. The engine is the m111

A few days after purchase an engine light came on. The used car dealership I bought it from booked it into a garage round the corner. The mechanic said the code referred to a vacuum leak but he couldn't find any leaks and to come back if it came back on.

It did come back on about a month later, this time it was a p0172 code "running too rich". I left it with the same garage and he told me cleaned the sensor (presumably the MAF)?

It came back on about 4 days later and this time the dealer booked it into a Mercedes specialist. I left it with them and they said it wasn't telling them much and because they had a spare part lying round, they replaced the equivalent part in my vehicle with that spare one - again think it was a sensor or something.

Lo and behold, a few weeks after the sensor was replaced, the light has come on again and it is booked back into the same mercedes specialist.

Any ideas on why this keeps happening?

 

[BlackC55]

Its happening because it hasn't been fixed properly.

I expect there is a intake leak or oil in the wiring loom. Do a search on here. Loads of info about it.

 

[ChrisA]

Lo and behold, a few weeks after the sensor was replaced, the light has come on again and it is booked back into the same mercedes specialist.

Any ideas on why this keeps happening?

It's because they're not really Mercedes specialists

 

[famasfilms]

Its happening because it hasn't been fixed properly.

I expect there is a intake leak or oil in the wiring loom. Do a search on here. Loads of info about it.

I'm in Southampton, so if it comes back on after I get it back from them today, I'll give you a call!

 

[famasfilms]

I should also add, since they replaced the sensor the car was a lot more economical.

Instead of filling up every 2 weeks, I got roughly 24 days driving exactly the same journeys/routes

 

[famasfilms]

I got the car back yesterday evening.

They said the engine light was back on again because of the same code p0172 - running too rich

Their fix yesterday, seemed to be more on the configuration side - changing settings of the car to make sure it did not run too rich.

Does this sound right?

 

[tjs_riley]

Do you know WHICH sensor they replaced ?

 

[BlackC55]

I got the car back yesterday evening. They said the engine light was back on again because of the same code p0172 - running too rich Their fix yesterday, seemed to be more on the configuration side - changing settings of the car to make sure it did not run too rich. Does this sound right?

Nope.