my car is running a little rich.okay badly rich. i can smell the gas in traffic along with burnt oil. any one know how to fix the running rich part.car studders when i 1st start it and back fires some times the o2 sensor for my car is new as of 3 weeks before i got it. the back fire i hear is not loud or bad sounding it is kinda like a little pop

 

dont know if this helps but my speedometer bounces at low speeds

 

The speedometer bouncing is from your speedometer cable....and there is a fuel adjuster inside of the engine bay. I am sure if you do a search you can find some answers.

 

That sounds very bad. I don't think that's an adjustment issue if it is popping. Where is the sound coming from?

 

tail pipe it is not loud at all it dose it when it is cold out.or if i left my car sitting for a long time.

 

Sounds like a misfire. Run a compression test and make sure you didn't burn a valve.

 

thats the thing i am poor as hell and have no money looking for a easy way to fix 1st that dose not cost money

 

Take off your air filter and you should see the idle control sticking out next to the air intake. Mercedes make a tool to adjust it but you could see what you can do to without it?

 

oh wow thanks i still have the tools for my car. sorry i did not reply for a day i did not sleep for 48 hours