Check engine light came on in my ML320 (99). Codes read Fuel Trim Malfunction in Bank 1 & 2. Codes are PO173 and PO170. Can someone help to explain this and what needs to be done?

Type in P0173 in search and you'll have plenty of reading.

Fuel trim means that the computer has reached the maximun mixture adjustment. Vacuum leaks, fuel pressure, OR air mass sensor are the most common problems..

95% of the time the air mass sensor is the problem...112-094-00-48

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MERCEDES Benz Master Guild Technician (6 TIMES)
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Thanks. Is there more than one MAS. I am showing codes on Bank 1 & 2

ONLY 1...as listed MB number 112-094-00-48

__________________
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 MB Doc. Today CE light has gone off? Should i still be concerned?

Dear MB Doc.

I have the dreaded po 170 fuel trim bank 1 (only that code) in my 1999 ml320. I have changed the MAF... (ebay's). It worked for a while, now the truck hesitate upon aceleration it turns off, I have to give it gas to turn it on, stalls, you name it...
Pls help

Do you have CEL or pending codes?