Volvo 850 94 Black smoke from exhoust heavy gas use, replaced air mass sensor, inspected injectors, all ok. siill black smoke from exhoust. Need help!!!

Sorry, here is the original Volvo part #'s are 9202719 (front) and 9202721 (rear).

1997 Volvo 850 GLT FWD

I have had the exact same problem plus a horrible smell coming out of my muffler. Had advanced auto parts read error code and turned out that my oxygen sensors were faulty - I thought I'd save money by buying aftermarket replacement part from ebay - got a code P0171 and, subsequently, P0172 codes that replaced the previous P0131 P0133 codes. Excessive use of fuel including sputtering from the muffler. I found a seller on Amazon who carried OE Bosch sensors 15 097 ( front of catalytic converter - also called upstream ) and 15 062 (rear - downstream) $180 for both. AFTERMARKET or Universal sensors did not work for my car. Once I replaced them, I get great mileage, no smoke, no smell. Dealer wanted over $600 for the sensors alone and the installation was going to be $125 per hour and possibly a replacement of the converter. I replaced it myself for just under $250 including the aftermarket sensors. It took less then 30 minutes with a drive on lift.

Hope this helps.

Yes, I am a woman and am tired of being taken advantage of by mechanics:).

Keep it up and you will need a new cat converter and O2 sensors.

Rich running can come from broken, cracked vacuum lines, a bad fuel pressure regulator, bad engine temp sensor, bad thermostat, etc. If the dash temp gauge reads normal, then I would start by checking all vacuum lines going to the intake manifold.

Check the vacuum line from the fuel pressure regulator to the vacuum tree. If there is gasoline in it, you need a new FPR.

Klaus
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