Have you checked for fault codes? Try Forscan for Windows and a laptop with
https://forscan.org/home.html and
https://www.obdlink.com/products/obd...x/?ref=forscan or
https://www.amazon.com/dp/B094Z7PBLS from Amazon or ebay. They are renowned for DPF issues that can put them into limp mode see
https://www.youtube.com/watch?v=yop_WFCHvuc and
https://www.youtube.com/watch?v=9Tm_y02fGPw The also known for developing EGR sytem leaks but these usually also usually have associated coolant losses. Probably worth scrolling through all of Alan Howatt's MK $ Mondeo videos just in case too
https://www.youtube.com/c/alan4x6677...k%204%20Mondeo
EDIT: if you have the 2.3 Liter Mazda engine all of the above except scanning for fault codes is probably irrelevant.