I have a 2000 Mazda MPV that had a cracked exhaust manifold. I took it
to the dealer and they replaced it under warranty. However they still
charged me $85 to run the OBD codes. I know, I got ripped off. I just
went to AutoZone and ran the codes myself and came up with P0031, P0051
and P0037. These all indicate failed O2 sensors. Shouldn't these
failures be related to the cracked exhaust manifold?

Basically, I want the dealer to refund my $85 and reset the Check
Engine light for free. From my research they usually charge about $100
because you have to take apart the dash. Great design.
Thanks in advance.