Code clearing after MAF swap
 

(2000 CLK430 Cabriolet)

Does a tech need to manually clear the error codes (170 and 173) after replacing a MAF (mass air thingy).

Note: the MAF was NOT generating a 'Check Engine Light' condition. Only error codes (I failed emissions cuz of the codes).

'Check Engine Light'
 

Hello,

Just disconnect the +ve battery terminal, have a beer and reconnect.

Usually resets?

Brian

Any OBDII scanner will erase those codes. Ask local Autozone to scan it for you (free) and erase them.

it's wise to have a benz tester on it to reset the self adaptation parameters.

Some guys disconnect the battery and start the car ten times.

I always like to replace the big rubber O-ring that cinches around the mass airflow sensor to give it a nice tight seal near the holding clips.

Have seen techs get burned by replacing the maf sensor when the weak O-ring was the original problem in the first place.

Just like any o-ring, they can get sorta squared on the edges and not make a good seal any longer.
That's why I get one every time I replace a sensor so there is no chance of it sucking air at that seal area.
The o-ring cost only about $2.oo.
Part # 028-997-97-48.
Take this part# with you because it's not in the main parts info, they have to look it up in the micro-fische.

I understand the adaptation values will be reset/learned after ~30 miles of normal driving?

After a number of cycles,turn on, turn off, the check engine light should go off.

Mine did, but do not recall the number of cycles.

2000 E320 65,xxx