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Discussion Starter #1
hey all, i have already learned alot on here and now i have a new problem. i have a 2000 c230 komp. 64,000 miles , auto trans. ..i have changed every fluid and filter and spark plugs in it about 65 months ago. no problems until all of the sudden i got the dreaded check engine light after it had been idling in park for about 5 minutes. 20 degrees outside. so , after shutting it off for about 4 hours, opening the gas cap a few times, checking all fluids and such, i drove it again and the light was still on. so i went straight to auto zone and it read code P0170, and the code said the following: the PCM has determined that during testing the fuel value for bank 1 exceeded the specified range (bank 1 identifies the location of cylinder #1, while bank 2 identifies the cylinders on the opposite bank).
definition :
Fuel trim bank 1
explanation:
the powertrain control module uses the oxygen sensor to calculate the air/fuel ratio of the engine. the computer has recognized a rich or lean condition of one engine bank only.
Probable causes
1- if bank one and two codes set together suspect fuel or MAF sensor
2- oxygen sensor failure
3- ignition misfire-repair
4- fuel injector problem

OKAY COULD SOMEONE USE THIS INFO TO TRANSLATE IT INTO ENGLISH FOR ME AND TELL ME IF THIS SOUNDS LIKE 1 PARTICULAR ISSUE OR COULD IT BE MANY THINGS? what do i need to check first ( the easy/cheap stuff) .the car still runs the same as before , no problems, just a light. is it possible to turn the light off or will it just immediately return again? i did accidently over fill the gas tank about 100 miles ago and it spilled onto the ground ( the pump did not turn off on its own). could that be related in any way to this light?
any ideas from anyone? thanks alot :)
 

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Since you only have one bank, I'm leaning heavily towards the MAF. It goes more frequently than the other items, and misfires typically translate to their own codes.

Accidentally overfilling the tank could create some issues, drive it for a few days and see. If the codes clear the light will go out on it's own.

FWIW, be careful about overfilling on MB cars, you can easily destroy the vapor recovery canister (different code, though).

Take care and enjoy the ride,
Greg
 

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My MAF had about the same mileage when it tanked, same code, at least you haven't gone into limp mode yet as mine did. Some people have had some luck cleaning the element. I finally purchased a new one and had the other rebuilt for a spare. B
 

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Discussion Starter #4
how do i go about cleaning or repairing the MAF sensor? can i just take the connector apart and spray it with contact cleaner? what are my options if it is the MAF?
 

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how do i go about cleaning or repairing the MAF sensor? can i just take the connector apart and spray it with contact cleaner? what are my options if it is the MAF?
You can buy some electronics or MAF cleaner from auto parts stores. That works only some of the time, but it is worth a shot at 6 bucks a can. Remove MAF and spray inside of tube/element, etc. If that fails, a good MAF from autohausaz or other or ebay (if you are feeling lucky).
 

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Do as they say and get some maf cleaner, use it on the throttle body too and the temperature sensor, clean everything it's all very sensitive and can give false readings when dirty. Mine backfired with the nitrous and ruined everything until I cleaned them, now it's fine:)
 

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Discussion Starter #9
okay , i thought i knew where this stuff was but i looked under the hood and i am not sure where the MAF sensor is and the temperature sensor. what do i have to disconnect and such and where do i look to find these? thanks alot
 
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