^^

I really agree with you Pesuazo!
Thats why I dont understand nothing...
I paid a specialized mercedes mecanic to find the problem 1200$Can, he didnt find the source of it! So I started searching myself by doing all the possible diagnose test, now it does almost 1 year and I still didnt find the problem!!


I changed the spark 3 month ago, and beleive me: the spark are perfect! Brown!
The scope graph is also perfect! (it indicat a perfect mixture)

AND:
The O2 is giving me the correct value!! BUT like you I was having BIG doubt about a correct mixture (even with all the problem) SO I deceided to put a brand New O2 sensor, result: the same reading = a perfect mixture!!!!

I went trew all my ressource, that is why this tech forum is my last resolt...

Beleive me: it smell fuel at the exhaust and I have some major misfire if I have the bad idea to press full throttle when engine cold(30C)!!

The 4 cylinder condition seems to be the exact same: 'cause the scope gives me the same reading to the 4 cylinder secondary ignition AND the 4 spark plug has the same condition.

BUt still that headack fuell smell!

EDIT: And it really comes from the exhaust, raw fuel! Also the lack of power and low mileage...

help...please!