Help please

Need help with my truck

Hey Scotty, I’ve been watching your videos for about 2-3 years now to learn more About cars but i had a question for you about my car (2001 f-150 XLT) so my truck has been shaking pretty rough when it’s in reverse or idling and when I noticed that, I took it to the mechanic and they told me that one of the pistons wasn’t working, so I got that fixed and then that only stopped it for about 2 days, I brought it again and they told me it’s the oxygen sensors, so I got those replaced and it’s still doing it, my question is are they scamming me or is the truck just too old to repair? If so, how do I fix it or what is the problem. It’s not the vacuum tubes, they checked that too. Thanks and keep up the great work!

anyone can fix anything if they are honest and smart. I would advise finding better mechanics first, guy like me, then see what they say about value of truck and what it REALLY needs