The service light worries me -- pull the error code, because 2004 is a year where two piece spark plugs had a lot of problems, and it takes some finesse to replace the plugs without snapping them and turning the job into a full engine rebuild...

 

Just got home to read all of these responses....I am overwhelmed by how helpful all of you are. I really appreciate it! After reading all of them and talking to my son (the mechanic who is out of state), red flags are waving so I will be very careful.

Again, thanks y'all for all the advice. I will post the results tomorrow when I talk to my mechanic.

 

Ok, update. Spoke with my mechanic...he said the following:
--Service light wasn't on but there is a brand new coil that was put on which probably made sensor go off. Don't ask me what coil cuz honestly I am not fluent in this stuff (YET!!)
--Vibration was from no "guard" on exhaust. Whatever that is.
--Front brakes new...bad brakes bad & need replacing.
--Turn signal worked just fine for him...(of course!!)
Also found a cracked flood light cover.
So....will talk to owner tomorrow & run a carfax also.
Again....thanks for all the help guys!!