Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help

Go Back   PeachParts Mercedes ShopForum > Technical Information and Support > Tech Help

LinkBack Thread Tools Display Modes
Old 08-31-2005, 11:00 PM
Registered User
Join Date: Jul 2004
Posts: 121
OBDII Codes PO156 & PO161

My 1999 ML320 displayed Check Engine Light, it went on and off a couple times. At the present time, the light has been off for more than a week. OBDII reader scanned code PO156 (bank2, sensor2) and pending code PO161 (bank 2, sensor2). Is the O2 sensor defective? Or might it be a wiring? The car has only 49k miles.

Thank you.
Reply With Quote
Old 09-01-2005, 08:03 AM
Join Date: Mar 1999
Location: Tucker, Ga USA
Posts: 12,153

You need a left rear O2 sensor!
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
Reply With Quote
Old 03-11-2007, 09:17 PM
Registered User
Join Date: Jul 2004
Posts: 121
I had a dealer replace the left rear sensor (was throwing PO156 and 161 codes). About a year and few month later, CEL came on and now I have PO161 again(O2 sensor heater circuit malfunction) and pending code PO173 (fuel trim malfunction) stored. And it is the same bank and sensor again. Should I replace it again or is it an indication of something else going wrong?
Reply With Quote
Old 03-13-2007, 08:32 AM
Registered User
Join Date: Jul 2004
Posts: 121
Anyone? I suspect it might be Mass Airflow Sensor, but I wanted to confirm with you folks first. Thanks.
Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Interpreting OBDII Codes deanyel Tech Help 7 08-10-2005 10:25 AM
OBDII codes supradupe ML, GL, G-Wagen, R-Class, Unimog, Sprinter 4 10-08-2003 09:35 AM
OBDII codes wanted Thomaspin Tech Help 0 04-02-2002 02:37 PM
Fuel Trim? OBDII cycle and CHECK ENGINE ? ke6dcj Tech Help 1 08-06-2001 08:54 AM
Two OBDII Codes Found, What Now? atikovi Tech Help 3 04-16-2001 06:30 PM

All times are GMT -4. The time now is 06:51 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page