Cadillac Repair Questions? Ask a Mechanic for Answers ASAP
hello . I can assist you with this . Is your MIL light on ? ( Check Engine )
when you step down on the accelerator hard do you hear a loud intake sound . Kind of a " DEEP throaty" sound from under the hood . Can you scan the vehicle for DTC's ? ( codes )
it sounds to me that you have a plugged catalytic converter , that would lead to the O2 sensor code . I would have your mechanic check for that . Disconnect the exhaust before the Cat and see if that cures the problem .
That is the most likely cause for the symptom you are describing .
how are you coming along with your problem ?