The dash should not have to come apart. The port for the OBDII machine
is usually under the dash on the drivers side and takes only a few
minutes to reset the codes. The dealer should have done at least one
of these 2 things: 1) Have the diagnosis included with the warranty as
the codes derive from the warranty work. 2) If they cannot include it
with the warranty and are not willing to cover the diagnostic cost then
the codes get reset after the warranty work because it is part of
scanning it in the first place and you paid for it.

Sidney wrote:
> 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.