o2 sensors/check engine light

[ibarra]

my light came on my 94 tbird and i ran the test and it said my o2 sensors where running too rich so i replaced both o2 sensors and now it runs like it has no power at all (when i barely give it gas)and the light still comes on even though i cleared it with the ecc machine. i re-did the test and it said o2 sensors where running low people said i needed to brake them in (o2 sensors) is that true? and also when i start the car (when its cold) it strugles to turn on and its starts to raddle and sound as if it was caburated not fuel injected then 2 seconds later it goes to normal...does anybody know what i can do. i would really apreciate it

[brooster]

What engine? What else have you checked?

The O2 is an informational sensor as a rule, but can/will affect driveability if defective. When the O2 is rich, this means that the O2 is telling the computer, "hey we're getting too much unburned fuel down here".

The question is why? Is the fuel pressure too high because the regulator is sticking or the diaphragm is blown through? Are the plugs worn out and not properly igniting the fuel? Is the air filter stopped up or maybe the Mass Air Flow meter is telling the computer there's more air going into the intake than there really is? Is the coil working properly?

Now that you've replaced the O2s (No, you don't have to break them in) and plugged them in properly, you're now getting a low/lean code if I understand you correctly. This could be an indication of not enough fuel (restricted fuel filter, weak fuel pump), too much air (snorkel from air cleaner not connected properly with clamps, a vacuum leak, etc.) or faulty MAF sensor.

The coolant sensor could be providing the wrong information.

Start here.

Check the fuel filter for restriction. After draining all the fuel from it, blow through it. It should be totally free of restriction. If not replace it. If you can, check fuel pressure.

Make sure all hoses are installed properly from the MAF sensor to the throttle body. No holes or tears and clamps are tight.

Make sure the air filter is not filthy or excessively dirty.

Make sure all sensors are not broken and are plugged in properly.

Unplug the MAF sensor and try to drive the car. If it's better, plug it back in. If it runs worse with it plugged in than it does unplugged, you've found your problem.

[ibarra]

its a 3.8
also about a year ago i added a k&n filter...could that be why it may give it so much air...i was planning to change the fuel filter.....ill try the maf disconnected and see what happens thanks a lot i really appreciate this