We have a 1997 Mazda 626 LXi 2.0 and we've been having a problem with losing power we've had a full service done a diagnostics done and even a Mazda service center try and find the problem and they said it was the center pipe and back box of the exhaust we took those off and it still does it. Now he even took the catalytic converter off and put a straight pipe in and it still does it...Any suggestions what it may be now? We're stumped..and my husband is mad that the Mazda dealer said it was the exhaust and it wasn't. Please help!! Carey