First, thank you all for your time.
I took my ST to the auto part and they connected the scan tool, results were: cylinder 4 was misfiring and the rest were having trouble running under low rpm (1000rpm) and it had an air leak, i forgot to get the code numbers :toilet:.
The guy sugested to replace the spark plugs and try to find the leak. I replaced the spark plugs and had no luck, same problem but the "check engine" light disappeared wich is now a nightmare because my ST is now sitting in my mechanic parking lot waiting for the "check engine" light to come on so they can plug in their scan tool and find out exactly what it is :sad:
Mechanic said to drive around like that until check engine light comes on, i say: :cheeky: i don't want to drive like that and cause anymore damage. What else could it be? If one cylinder is not working and the others are having problems under low rpms how about the ignition coil?... Maybe an injector?
My ST is a 2003 premium package with 208.000+ miles :grin: never changed the ignition coil or the injectors, i had use seafoam in the past not to long ago, the truck was working perfectly strong and all of sudden at a stop light without any notice just begun to struggle.
Sugestions please?