Need Help
 

My 1991 190E failed inspection for emissions. Can anyone tell me how many Oxygens sensors ny car has and if there is a resonably price MB repair shop in Central Jersey.

Simple 3 wire O2 sensor.. only 1 sensor

Thanks are they hard to install

It is a grubby under-the-car job, with a 7/8 inch wrench in an awkward position, but not complicated. However, your problem is probably more complex than that. Has it recently had new spark plugs and spark plug wires?

Andrew
1989 190e 2.6

I have a CEL on my 91 190E 2.6L, I was guessing with 109 on the clock it would be due for an 02 sensor but what else are you thinking of?

what i found out is the O2 sensor has 3 wire, 2 are for a heater to keep temp constant.
The third will be power to the computer.
The O2 sensor is thermo-couple device= gives off electricity when heated. Same deal as in most gas heater, power to turn on gas, make it a safe unit.
The median voltage is 450 millivolt, too low = lean engine the Computer will dump more gas so it will be overly rich,

high voltage the computer perceives it as rich so it will lean out the engine.
next week i am trying to hook up a small battery to the O2 sensor wire to see if i can beat the BC emission too. We call it Aircare here, or airscare.
Is going away in a couple more yrs. That will make life a bit more easy for weasel like Yours truly.

The computer should resides in the right front passenger foot well, u pull the carpet, a black hard plastic there, a small 10 mm nut to undo it. The comp should be there.
A wire should come thru. This is repost from someone else.