i get flames from under my car and from the muffler. more exhaust gas goes out the muffler than through the midpipe. air goes to the least resistance which should be out the muffler also is there a sort of a suction going out the muffler to suck more of the air back in from *reversion* of the air. probably the wrong words used but some ideas.......

Are external WG's louder?

If they're atmospher dumped then yes. If they're rerouted back into the exhaust system, then I've heard wastegates that when opened, made the car QUIETER...

The composition of gasses should be the same. After all, if you worry about that then you should also worry that the gasses close to the wall of the pipe are different than the gasses passing down the centre of the pipe. Since your O2 sensor only samples gasses from the side of your exhaust pipe you could argue that they would be different from the faster moving and higher temp gasses in the centre of the pipe.



the exhaust gasses would have to seperate in a very short time for some to go out the wastegate and others to go out the exhaust. I don't think it's possible.

I thought Air/Fuel Ratio Monitors had problems reading on deccelaration after a long hard pull. I was told that widebands will often display an error or read "-LEAN-" or something on the LCD display when under heavy deccelaration.



Anybody else able to confirm who has actually installed a wideband o2 monitor in their car or has seen one operate in person???

Correct.

easy. tune at 15/20psi with the 15 psi spring then put in a 10/12psi spring and report back your findings.lol

and yeah my friends have commented on fire/flame undernneath teh car as well as through the muffler...

With the injectors being turned off on deccelaration, you expect the WB to read lean.