i have a c220, with a code p0170 fuel adaptation out parameters.i replaced the mas airflow sensor, and this fixed the problem for about three weks. then the same code came ba ck . can antone help me????? it is a 95 c220

Since there are at least 6-7 things that cans cause that code...you need more info..like reading live data from the stored info in the fuel computer.

IS the fuel adaptation at RICH or LEAN limit??

OF course a MBUSA reman air mass sensor might STILL be the problem!

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
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Mercedes Benz Star Technician (2 times)
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27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
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thanks for the info.is there any other way of finding out what is causing this p0170 code (shot term fuel adaptation out of parameters),other than probing pins?????

Logical analysis of real data. Start by answering Doc's question.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

95 c220 thanks again for your help, i think that the car is running rich, you can hear the fuel pumps cycling on and off while car is idling.also would a bad fuel pump relay cause this to happen????? thanks again.....

You don't need to probe pins..but you need someone with a scanner (NOT ODB2) that can read live data thru the fuel system computer (HFM).

MOST likely problems include vacuum leaks/fuel pressure/fuel quanity/engine temp/air mass sensor/oil consumption..

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Thanks for the information doc,it was very useful.....MR.BENZ