ok guys here is what i am dealing with: I recently bought a 2001 mustang 3.8 V-6 used from an individual(this car was bought for my 17 year old Daughter). I made a good deal on the car and new it needed a little work, powersteeering pump whining, muffler sounded louder than normal, and a few interior cosmetic fixes. the car was in good shape, ran good, no smoke, dry underneath. well i get the car home and start on it. First the "service engine soon" light comes on. so i have a friend that does mechanic work on the side puts it on his scanner it shows an EGR code. He clears the code and recommends a Seafoam intake cleaning. he also tells me that someone has removed both Cat converters and that is the reason for the loud exhaust( converters are gone but the O2 sensors are still there). I do the seafoam cleaning and bring it back to him (service engine light came back on) so we pull the EGR valve and end up changing it. he tells me to drive it and see if the light comes back on. it does of course so he clears it again and i try to get it inspected and failed emmisions computer tests. I have saw on the forum about the EVR sensor, and the DPFE sensor may be bad, my question is what does removal of the converters do to the emmissions diagnostics?, will i need to put the converters back to pass the emmisions test? i have noticed the car runs rough when you hold the throttle between 1000 and 2000 RPM but only when the a/c is on. is this from the emmissions problem? any help will be greatly appreciated!!