1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Clk200K high CO2 and P170 code.

Discussion in 'Engine, Drivetrain, Fuel and Exhaust' started by Ryannn, Jun 6, 2018.

  1. Ryannn

    Ryannn New Member

    Messages:
    8
    Likes Received:
    1
    Joined:
    Jul 1, 2017
    Your Mercedes:
    C209 CLK200 2005
    Hi everyone,
    Hoping someone can help me with a diagnosis.

    Had an EML come up on my 2005 CLK 200 recently. Read the code with my cheap reader and it’s showing 2 codes, “NA” and “P170”.

    Took the car for MOT today and it’s failed on CO2 emissions at 2%, all the rest were fine.

    Any ideas where I should be troubleshooting? Car’s been fault free for over a year!
     
  2. John Laidlaw

    John Laidlaw Senior Member

    Messages:
    15,643
    Likes Received:
    3,452
    Joined:
    Nov 15, 2013
    Location:
    Wirral
    Your Mercedes:
    W212 E63 ///AMG V8 Biturbo Volvo XC90 2018
    Fuel and air ratio must be off- timing or maybe spark plugs or leads is where I’d start I guess, but your codes don’t mean anything you can work on, so best get a diagnostic with a Star machine at a Mercedes Independant
     
  3. Oldspanners

    Oldspanners Senior Member

    Messages:
    219
    Likes Received:
    119
    Joined:
    Oct 30, 2017
    Your Mercedes:
    C CLASS 2004 C180
    I had the same codes.
    Turned out to be firstly the after cat O2 sensor faulty and oil leaking from the cam magnets into the wiring harness.
    A good place to start, other than obviously getting a Star diagnostic, is to disconnect the after cat O2 sensor below the car and look for signs of oil contamination as it's the lowest point. There may also be signs of oil at the engine ECU connector.
    If this is your problem it's all easy enough to fix for the DIY mechanic.
     
  4. OP
    Ryannn

    Ryannn New Member

    Messages:
    8
    Likes Received:
    1
    Joined:
    Jul 1, 2017
    Your Mercedes:
    C209 CLK200 2005
    Cheers for the replies. I had the oil contamination in my old CLK but it got written off before I could fix it!
     
  5. OP
    Ryannn

    Ryannn New Member

    Messages:
    8
    Likes Received:
    1
    Joined:
    Jul 1, 2017
    Your Mercedes:
    C209 CLK200 2005
    Ok, I have an update!

    Took to an MB specialist for diagnostics. No faults found other than the pre cat Lambda reading high. They had a good look round for vac leaks but couldn’t find anything. So suggested next step is to change the sensor and take it back...

    The plug for the pre cat Lambda is buried behind the engine, what’s the best way to get to it?
     
  6. Oldspanners

    Oldspanners Senior Member

    Messages:
    219
    Likes Received:
    119
    Joined:
    Oct 30, 2017
    Your Mercedes:
    C CLASS 2004 C180
    If it's the same as the C class it's on the left hands side of the gearbox mounted in a plastic clip. Access from below the car after removing the rear plastic under-tray. Tie a piece of cord to the end as you remove it as it makes it a lot easier to pull the new one in over and around the back of the engine and bell housing.
     
  7. OP
    Ryannn

    Ryannn New Member

    Messages:
    8
    Likes Received:
    1
    Joined:
    Jul 1, 2017
    Your Mercedes:
    C209 CLK200 2005
    Evening everyone,

    I’m going to bump this rather than start a new thread.

    Recently changed the Lambda sensor which hasn’t fixed the fault. What I did notice however is that I’ve got oil in my Lambda plug. Checked the cam magnet plugs and there’s oil in both the inlet and exhaust. However there’s no oil in the MAF sensor and a tiny amount in the ECU plug.

    So I have two questions...

    I’ve changed the o-rings in the cam magnets, will this now stop the flow of new oil into the loom?

    I’ve been to Mercedes today and priced up a new engine loom at £400, I’m happy to pay that as it’s a tenth of the cost of replacing the whole car! But, should this go towards fixing the issues with my lean running? Or have I just found the issue before it develops into a problem?

    Cheers,
     
  8. Oldspanners

    Oldspanners Senior Member

    Messages:
    219
    Likes Received:
    119
    Joined:
    Oct 30, 2017
    Your Mercedes:
    C CLASS 2004 C180
    I cured it by fitting new cam magnets because they leak internally, fitting new o rings, small plugs and blockers to the wiring. I don't think you'll need to change the harness as you say there isn't that much oil but you will have to clean the after cat O2 sensor plug and the ECU perhaps 3 times with contact cleaner (don't squirt it into the ECU use something like cotton buds and ensure you don't bend any contacts or leave fibres behind) before it's clear especially the O2 sensor as it's the lowest point.

    Camshaft Magnet Wiring Harness A2711502733
    Engine Camshaft Magnet Seal O-Ring A0109972348
    Engine Camshaft Magnet Grommet A2710510032
    Engine Camshaft Magnet A2710510177
    You'll need 2 of each came to about £150 from memory in MB Newcastle.
     
    Last edited: Aug 30, 2018
    Wighty likes this.
  9. OP
    Ryannn

    Ryannn New Member

    Messages:
    8
    Likes Received:
    1
    Joined:
    Jul 1, 2017
    Your Mercedes:
    C209 CLK200 2005
    Thanks for that, I read a couple of other threads earlier on that said the same aswell.

    I don’t fancy taking the magnet apart so I’ve ordered one (I already have a new one from my last clk) and two of the blockers. I gave the ecu plug a clean the other day, it’s only in the rear plug so I’m just hoping I caught it?
     

Share This Page