Weird Idling- O2 sensor gone??
 

I have a 2004 C230WZMT or Sports Sedan w/ a manual tranny. (with 65,000 miles on it. Yes, I drive a lot!)


So I noticed this morning my car is idling high, around 1200 rpm. If I come to a stop, and let the clutch out a little, putting load on the engine, it'll come back down, and stay down......but it's not really settling at the 550 rpm idle rate. It's even dipped below that, not a complete studder, but it did occur twice. The car is so quiet in the cabin, you have to watch the TACH or open the window to even notice it. So it might have occurred longer then the past couple of days.........


And I at the same time I noticed a 'noise'. I think it could be a belt, I'm not sure, it only made the noise, say, when coming to a stop with no throttle. As soon as I applied thorttle, it would go away.......and it's NOT consistant. And it's not, as far as I can tell with a little testing, a power steering pump, like how you always hear on a FORD. I've even shut off the A/C unit, which is designed to be on all time.....

But.......could it be, maybe a low brake fluid resevoir? ...or power steering???


Car doesn't require a tune up until 100k.....so I'm not sure wtf is going on with it. And I'm confused on the idle issue, could it be a throttle cable sticking??

Weird how if when at a stop (and it's idling high), and I let the clutch out to put load on the engine, it dips (naturally due to the load) but then it (the idle) will come back down. Sometimes going back to normal idle rate.


Suggestions,questions or observations on either or both subject matters?


Thanks peeps!

And thanks for having me in the forum!!

From what I've heard from others on different forums, people think it could be the 02 sensor. But does my car have TWO? And does this seem like it could be the culprit?


THANKS AGAIN GUYS/GIRLS. Merry Christmas!