Dyno session on my M3 at Gintani 2/17

[Jonmartin]

I went to Gintani Motorsports to Dyno E90 M3 on their Dyno Dynamics machine. I have no mods other then a front cat Delete. I had a CEL at the time which might have caused my car to lose a lil power on top of it being the "Heart breaker" dyno. Notice the AFR at 12.2 at the end of the runs which is pretty rich for N/A. Here are the graphs.

[Jonmartin]

Originally Posted by PencilGeek

AFR from a tailpipe sniffer...right? You didn't actually measure before the cats...did you (somewhat rhetorical question because the M3 doesn't have a bolt-on place to measure AFR before the cats).

What good is measuring AFR from a tail pipe after two sets of cats, and after the ECU already compensated for what it found in the O2 sensors? Seriously, those measurements are practically meaningless. Comparing it to some other tailpipe results doesn't mean much either.

Are you saying that tailpipe sniffers are pointless and play no role?