Lincoln/Mercury Repair: 97 merc. cougar 4.6 L Engine Idle rough...., air filter oil, oxygen sensor

Question
Hello and t/y 4 ur time.. My question is I have changed the plugs and wires. Air filter,oil change...  And the car still runs rough. at an idle is the tach. is low and it like chugs on take off i hold it to the floor to see what it wil do and it shakes bad but still has power.. Thinking that w/previouse experiences that it could be the oxygen sensor is bad..??? could u give me some advise in which way to go for this?

Answer
hello justin
you can have all the expernince in the world and still be wroang i will tell you the same thing i tell everyone who comes in my shop get a diagnostic test this does not guess and i am sorry i do not guess i would be out of a shop . do your self a favor get that test it will save you money in the long run pete