1999 Mercedes Benz 320e Emissions

  • 1 POST
  • 1999 MERCEDES BENZ 320E

Engine Performance problem
1999 Mercedes Benz 320e 6 cyl All Wheel Drive Automatic 90,000 miles

1. Took the car in for emissions and it failed with codes:
P0170 Fuel Trim Bank 1 & P0173 Fuel Trim Bank 2.

What do these codes mean (if it the Oxygen sensor the car has 4). Also sometimes the has been mis-firing.

2. At what mileage do you recommend replacing the transmission fluid and filter, as it is a sealed system.

Do you
have the same problem?
Thursday, April 22nd, 2010 AT 8:23 AM

1 Reply

  • 17,507 POSTS


These are the possibilities but you will need a good quality scanner to read live data to test it. In general O2 sensors have a life span of approximately 100,000 miles give or take, you are close now, and one of these could be the problem, or it could be dirty fuel injectors, injector control, or even just a vacuum leak.
get a can of spray Throttle body cleaner, spray the vac lines and maniflod area, when the idle changes, youve found the leak! You want the engine running and spray on the outside but do direct the stream onto the hoses, if it is a vacuum leak, the engine idle will change speed, then you have detected a leak, repair the vacuum leak and see how it runs! Misfires can also be bad spark plugs, when was your last COMPLETE tune up? Fuel and air filter?

Was this
Thursday, April 22nd, 2010 AT 6:23 PM

Please login or register to post a reply.

Recommended Guides