Is this local car shop taking advantage of me?

It would be helpful if you would have listed the parts that were replaced and the year make and model of you car. All you have given us is your thoughts. The only thing I can say about your question is that the engine light would not wait five days to come back on if they did nothing towards fixing the problem.

I would change shops. Given 2 opportunities to fix the car and it's still having problems? How old is the car? If it's been manufactured within the last 15 years or so it should be storing a code that a modern shop will be able to retrieve from the car's computer with a scanner. There are car forums for just about every make and model car with some knowledgeable people on them. I'd recommend finding one of these forums for your car and asking about the problem you're having. They'd probably be able to help you find the code yourself by performing a pattern of steps that may include turning the ignition and/or pressing the brake pedal.

Please, when asking questions such as yours, include the year make and model of the car. We can't answer your question as you didn't list and of the codes from your cars computer or difficulty with the car as you drive it.

This is for your own benefit: The dealer of your car is best equipped to read your on-board computer. This is not to say there are well equipped trustworthy private mechanics who have UPDATED expensive diagnostic equipment to do the same thing.

A "good" mechanic should have explained if he was up against something his equipment couldn't pin-point and recommended someone who could.

Your words which say: (engine needs service soon) could be an older Ford Taurus or Mercury Sable. Sadly, their on-board computers do not store codes. The warning on the dash actually has to be illuminated on the dash for a Ford dealership to read the code correctly.

Do I think the garage your at now is taking advantage of you? Sadly this is a case of poor communication by the mechanic and you not writing down exactly what parts are being installed and all reasons for it.

Idid he tell you what parts were needed? How old/new is your car? What kind of car? If its and older car, then I could be difficult to find parts. But I believe you are being screwed. He could have not done anything and just reset your service engine light. If that's all he did then it would defiantly come back on. I'd ask him what he replace and what's wrong with it now, then go somewhere else and see what they say about it.

i think so, i suggest you take the car to a different shop.