Could a leaking exhaust manifold damage or give false readings from a O2 sensor?

[pjdm1980]

Could a leaking exhaust manifold damage or give false readings from a O2 sensor?
The car (S/C V6 VS) has had a leaking manifold for a couple of months now, but not to bad i can hear it with the window down. Now the car studders when cold on half way throttle when cold and i only replaced the O2 sensors about a year ago (4 WIRE) and it comes up with the same codes as last time this happened Code 44 - RH Oxygen Sensor Lean (O2) .

[moose man]

A leaking exhaust manifold will most definitely affect the readings of an oxygen sensor. After the exhaust valve closes, a low pressure is created behind the exhaust charge in the the manifold, and this is where extra oxygen is sucked in.

It won't, however, affect the driveability of the car any more than very very slightly. Oxygen sensors are only trimming sensors, and the engine can run perfectly fine without them, which is what happens when a fault code shows - the ECU disregards the signal and substitutes its own.

[Chiko2480]

I've just replaced a cracked exhaust manifold which I found when I got the ever faithful engine light error. The errors were 64 - lean reading & 76 - uneven fuel mixture between left & right banks. I though the new manifold would stop the error but I'm still getting the errors. I've just checked the pasenger (left) sensor & I was absolutley coated with so much soot I couldn't see the flutes in the tip. Cleaned it it a bit but still getting the error.

Any ideas anyone

[pillzor]

probably just bang in a couple of new ones, i just did mine and they `looked` fine but fuel consumption allmost halfed.