jtjtjt

ive got a 2001 c200 2.0 w203 . thecheck engine light has come on many times. when i take it to the garages they will say its the 02 sensor and they change it ( ive changed it about 3 times now).

today it has come up again. and the car is slower in acceleration and feals like it has lost power.

wats the problem?

Buellwinkle

Sounds like an O2 sensor, haha. Unless you like replacing O2 sensors on a regular basis for no apparent reason, you may want to invest a few dollars on an OBD-2 scanner (that's what they call them across the pond, may a have different name in UK). Also, many times a dirty MAF can cause fuel trim codes that are missinterpeted by inexperienced mechanics as an O2 sensor. Get a can of MAF sensor cleaner and have it. Many posts on this subject should you care to search.

magnus203

try the air mass meter, that would cause the o2 sensor to throw up a fault due to the air mass meter being faulty and overfueling causing the o2 sensor to be like "what on earth is going on" when the air mass meter is fubar loss of power is almost a defenate, and there will be a slight missfire also. if not, maybe your cat is fubar? which o2 sensor have you had replaced, before cat or after cat?

tbh. id concentrate on the air mass meter, or the catalytic converter.

DJ Kyro

Also check into your spark plugs. I had a similar situation. When the O2 sensor went bad it caused my engine to feel weird and ended up burning a spark plug. Check into that as well. I have a c180 with the 2.0 engine.

jtjtjt

i have changed the sparks. how do i clean the air mass ?

Ogpogo

Blow hard....or go to your local auto parts store and buy some MAF cleaner - Point & Shoot.

Buellwinkle

The most common in the U.S. is CRC MAF Sensor Cleaner. There's probably local brands in England that work just as well. Search the forum for instructions but your motor is the M111 which is very similar to what was sold in the U.S. as the C230 and SLK230 and the MAF is probably located on the right side of the car (facing the grill) and towards the front. It's part of the intake tubing, about 2" in diameter, black and comes out of the intercooler. You typically remove the MAF with a hose clamp on one end and some clips on the other and there's a connector with wires coming out of it in the middle. You remove the connector and then remove the insert with two security torx screws holding it in and clean the tip with the exposed gold wire with the cleaner, never touch it. Use a lot of cleaner, it's cheap, the equivalent of 3 quid here. Also change your air filter as that's the #1 reason the maf gets dirty. If you can't find MAF Sensor Cleaner, either visit the U.S. (exchange rate is good for you, and So Cal is much drier than London) or go to an electronic supply store and get Tuner Cleaner. Although some people try it, I would not recomend you use anything harsh that may damage the plastic and circuitry around the wire like brake cleaner.

benzmodz

The cam adjusting magnet is leaking oil into the engine harness, O2 sensor, MAF, Engine controller. Disconnect those cables, get a white rag and wash the connector and see how much oil comes out.

You need a full overhaul. Harness, ECU, MAF, O2, CAM magnet, special update short harness (stops the oil).

If the ECU is full of oil that could just die any old time. First sign is the cruise control not working.

jtjtjt

a local mechanic told me the exactly same thing. he cleaned out the oil from all those places and he cleaned out the ecu. i havent got a new ecu but he cleaned it out. i havent got a new maf either.

C230 Sport Coup

LOL. I'm surprised no one has ripped this guy for not saying what codes.
I thought benzdodz was kidding. I guess not.