jjrho

what does p0173 fault mean? i reset it and it hasn't come back but i failed the smog in calif due to resetting it/eng chck light off, and not driving it around enough to reset the whole system....
the smog computer alerted the operator that it was reset 'recently'....

no symptoms from the car...01 s500, 70K miles....


jim R

~CL500~

Could be a number of things causing this; dirty or faulty MAF sensor, vacuum leak, O2 sensor, even bad fuel. P0173 is a fuel trim malfunction for bank 2 of your engine. The fact that it's only on one side is odd; then again OBD can be odd at reporting. If it hasn't come back yet, that's good.

Some advice to those considering the reset to pass inspection; You can't reset the thing and expect to pass inspection immediately there after. When you erase OBD codes, your freeze frame data is also erased. Freeze frame data is the statistical results of numerous software programs embedded within the OBD system. When you reset, these programs show up as incomplete or not ready which makes it obvious that you just reset the system. These programs have algorithims that require certain criteria to be met for the program to effectively report on the integrity of the vehicle systems they are monitoring. Some of these criterion are acceleration, deceleration, sustained speed, etc. In a nutshell, drive the car for a few days, city, highway, stop and go, etc. Hopefully that'll do it. Then try to get re-inspected if your CEL is still off. Good luck

m4xm1l10n

Get yourself a new MAF Sensor . I'm 99% sure specially on that year car

jjrho

wow, good info...
u r right...i 'failed' due to recent reset... bad thing is he charged me full and reported it to dmv/calif state already...

i'll drive it for a few days and go back...

is there anything i can do to the MAF sensor? clean it or blow it out or something? is there one or 2 MAF snsors?

thanks for your help guys....

jim R
01 s500 70K miles so calif

Benz5656

I think I am having the same issue, where is the MAF located, i'm sure its not difficult to replace, and how much is the part?

ohlord

154 bucks at www.autohausaz.com delivered free.
The problem is not the i/m codes begin set to not ready,when you erase the codes it turns off the light but the code if left unresolved will remain stored in the cars ecu.Driving it for a couple of days will not clear the code unless it was a ghost code.Run the diagnostics with your obd2 scanner,see if they are still pending.If not then run the generic drive cycle program.You can find my procedure for it on benzworld.org w210 section,use the search function.