Hello, I recently took my 2003 Ford Escape to a mechanic ...

Hello and welcome to Just Answer! My name is \*\*\*\*\* \*\*\*\*\* I am here to help answer your questions. I am sorry to hear you are having issues with your vehicle. I will do my best to give you the answer you are looking for. Please allow me a few minutes in between our responses to review your information. I may ask several questions to get more details about your problem. While you are waiting for me to respond I am looking up the workshop manuals and wiring diagrams needed to answer your concerns. **The website will prompt a phone call automatically, not me. So please don't let this automatic service prompt annoy you. If you prefer to talk verses type then please use the phone call option.** Hello, it sounds like you have more than one problem. When they changed the exhaust to a flex pipe it can be causing the noise. The lack of power can also be caused if the flex pipe is the wrong size. A plugged catalytic converter can also cause a lack of power. The coolant leak will need to be identified to know what to repair. A shop would be best to look it all over if you do not know much about vehicles.

Hello Gene, thank you for reaching out and lending me some help and advice.

You are welcome, do you need more help with this concern?

How can I tell if the flex pipe is causing the issue or if the catalytic converter is the issue

An exhaust back pressure test would need to be done to check for an exhaust problem with the converter. The pip itself would need to be disconnected to see if that is the issue.

What about the catalytic converterI also have a loud whining when I turn my vehicle

It would need to be tested by a shop. The converter is part of the exhaust manifold. it cannot be disconnected to check. I am sorry but the question is limited to your lack of power concern. New questions need to be posted as a new post per the website terms of service.