what exactly is the code? unless you get a p1320 ignition signal, you should'nt need a coil. usually you get a misfire code with this problem. plugs are supposed to be good until 105k. CHILTONS labor guide says 9.9 hrs labor. however i'm sure mr. chilton has never done one LOL. i find that to do it correctly you really need to pull the engine and trans. getting to timing cover off while in the car is a pain, so i just pull it. cost me some time but its worth it to me. i've done so many that i can have it on the ground in an hour. plus you'll have the cost of parts, oil and filter, coolant, etc,etc. labor rates vary from area to area. expect $70-$100 an hour. hope this helps.