Oxygen sensor or...? 2004 c240
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2004 C240
Oxygen sensor or...? 2004 c240
Can anyone help me out? About 2 month ago, the "engine check" came on and the car started running strange. It would rev certain times and other times there wouldn't be enough gas it seemed and the car would stall, but not die, just start shaking at a very, very low idle. So I purchased a code machine, in hopes of finding out what was wrong the cheap way. It came up with a "throttle position sensor" and a "camshaft position sensor". I took it to benz, they claimed it was not the throttle position sensor but just the camshaft position sensor. After finding out the cost, I purchased it online and did it myself. Car ran fine. Next, about a week later, the car starts stalling again. Bring it back, this time they claim it's the "air flow mass sensor" Fine, brought it home and go it fixed (they wanted $700 or so, I did it for $55 plus a set of polygonal tamper proof wrenches). The engine light goes off, BUT it still is idling strangly. So here I am, 2 sensors fixed and now I'm thinking it's the oxygen sensors. By the way, the "check engine" light was off for about 5 days, then it came back on. Did I hurt the new "air mass sensor" by not fixing the oxygen sensors I wonder? Or is it even the oxygen sensors? When I hook up that machine, I get a bunch of code readings, all the same for the most part. They read: bank 1 and 2 too rich and too lean. Anyone?
Thanks!
Thanks!
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
What mileage has the car done? I would expect O2 sensor codes to throw up if it's the O2 sensors but one should understand that O2 sensors have a design life (if not contaminated) of about 80,000 miles before their cycle times are outside spec. No you did not hurt the MAF
Do one thing - unplug the MAF - this forces the car onto a default map - while not perfect this will tell you if the MAF is playing up. Drive the car with the MAF unplugged & see if it still throws air/fuel mixture codes. It will throw a MAF code which you can cancel later.
Final point until you check the above. Did you fit the correct replacement MAF??? Your pricing above looks low. There are MAFs on the internet that look right & fit but are profiled for VW/Audi - they will not work on a Benz
BTW - have you had another TPS code? Have you done a throttle reset?
Do one thing - unplug the MAF - this forces the car onto a default map - while not perfect this will tell you if the MAF is playing up. Drive the car with the MAF unplugged & see if it still throws air/fuel mixture codes. It will throw a MAF code which you can cancel later.
Final point until you check the above. Did you fit the correct replacement MAF??? Your pricing above looks low. There are MAFs on the internet that look right & fit but are profiled for VW/Audi - they will not work on a Benz
BTW - have you had another TPS code? Have you done a throttle reset?
Last edited by Glyn M Ruck; Apr 30, 2009 at 11:25 AM. Reason: typo
