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I just recently replaced my o2 sensor on my1990 Fleetwood Brougham, like i was told the gas was too rich causing black smoke and gas fumes to come out of the exhaust. Now its not as worst as it use to be, but i can still smell and see it a little bit. What could be my problem now???
 

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94 Fleetwood Brougham
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307, 305 or 350?

O2 Sensor won't CAUSE rich very often, rarely is it ever the problem (Delco sensors), if is often just reporting the problem and the ECM isn't responding or isn't able to.

Look for MAP sensor vacuum line disconnected/broken/leaking, bad MAP, bad coolant temp sensor, bad air temp sensor (TBI), bad thermostat, plugged air filter, stuck float (carb), leaking injector (TBI), high fuel pressure, bad pressure regulator (TBI), plugged catalytic/exhaust, exhaust leak prior to O2 sensor making the O2 think it is lean and richening it (doubtful), broken vacuum line to pressure regulator (TBI), canister purge allowing fuel into carb/throttle body. Worse case, bad ECM, or bad wiring to the injector (TBI).

Start there and see what you find.
 

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all that he said above, plus:

if your car has one, check the air diverted valve feeding off the air pump. you may not have one, i dont know.

if you do, make sure the right hoses are going to the cat/exhaust manifold/athmosphere as designed.

and that the vacuum line to the air valve solenoid has vacuum.
and that the intake filter to the air pump is not plugged. the filter is made of sponge glued to a screen. the sponge desintegrates and the debris goes to the pump and air diverter valve. TEST THE OUTPUTS.

make darn sure, 100%++++ that you are not pumping air full time to the exhaust manifold as that will fool the O2 and give you a very rich mixture.

lol




Cedy42 said:
I just recently replaced my o2 sensor on my1990 Fleetwood Brougham, like i was told the gas was too rich causing black smoke and gas fumes to come out of the exhaust. Now its not as worst as it use to be, but i can still smell and see it a little bit. What could be my problem now???
 
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