If you want somebody else to do it then try Autozone or another place like that. Depending on the state you can get your car scanned for free.
Pretty much any good mechanic shop will do that. Price will vary but don't pay more than about $50. Most places will do it for free if you let them do the repair work. Look for an independent local shop with good reputation. Be careful of shops that may recommend a lot of unneeded repairs or maintenance.
Go buy a repair manual for your make/year/model on a CD and a DRB 2 scan tool (those work on all makes after 1995). Those two will help you find problems along with the repairs required. Most poor running woes are due to worn ignition parts, dirty battery cables and clogged filters. There's some wear items take require periodic replacement such as timing belts, EGR valves and O2 sensors. The owners manual in the glove box and the CD will give the mileage for doing those to avoid bigger more expensive repairs if you wait too long, like engine damage, lousy gas mileage and poor performance.
Most of that work can be done with an inexpensive tools and torque wrench from Harbor Freight. If you rather have a shop do the work, go call the better used car lots for referrals. They like to use honest shops that charge reasonable rates for doing competent work in good time. Then take a drive by the shops and check out the lots. If they're full of vehicles then they're doing something right to have so much work. Steer clear of the nicer looking shops with few vehicles parked outside. From my experience they charge too much and are prone to cheat unwary customers over un-needed repairs to compensate for their lack of business.
expect around $60 - $100 USD, or do try auto-zone or for free.
sounds like pie in the sky, a reputable shop estimates repairs and answers questions readily. they will run tests as indicated. the car must be acting up so they can understand.
any tool used by any one is just that, a tool, its not all knowing and should not be confused with proper care and maintenance.
scan tools can only be as smart as their operator. the code must be in there. or you have to get the car to set it for it to be read.
live datastream can be read but you must know what to look at and what to look for. show them how to make it act up and save money
call shop and ask
A friend of mine told that there is a mechanic shop that can analyze problems with your car and tell you every problem you have and need to fix, is that true? If so what would you think the price would be to do that?
