Problems after replacing spark plugs and wires. Did these guys know what they were doing to replace the plugs and wires?

what they had to remove is called the plenum or upper intake to get access to the back bank of spark plugs, also this is where the spark plug wires run under. while its possible that this is the cause( the plug wires are very senistive to position on this engine) i would want to know what codes they are getting before i would condemn their work. i have seen several of these engines with higher miles(over 90k) that usually sey cylinders 1,3 and 5 misfires. codes are p0301,p0303,p0305. usually caused by the exhuast cam timing being off by a tooth. too many times ive seen even experienced mechanics just put the engine back in time and while the problems is gone for now it will return. in my experience this is caused by the hydrulic tensioner bleeding down and letting too much slack in the belt letting the closest cam to the tensioner(exhaust cam on back bank) to jump a tooth or 2. replacement of the tensioner assy is the best fix. of course without knowing the codes they are getting this is only a guess. if you can find out what codes there are it will help greatly

I agree James.

I replaced plugs,wires and ignition coil in. My 2003 hyundai santa fe 2.7 liter and its still misfiring in cylinder 1 and 4. What else is there that can be wrong?

Try and replace the coil pack with new high quality spark plugs and gap them yourself, good quality spark plug wires, that's what I did in my 2005 kia sportage 2.7lv6 also replaced air filter, it has been two years now since I did that and the vehicle ran like a top for two years , I had the same issues of the miss fire codes and check engine light , and rough idling, the new coil pack which cost me $150:00 usa, good NKG spark plugs 6 cost me $40:00 , and spark plug wires kia original equipment $75:00 usa , I was very lucky to have a friend do the job for $60:00 can you believe it ,?, it's a big job to get to the three back plus near the firewall , top half of motor has to be removed , you also will need replacement gaskets for upper air intake and manifold , my truck is running rough I'm about to change all of those parts again except the coil pack, it is working fine right now ., good luck ,john r.

Have someone check the cruise control wire. There are 2 cables on the back, by the fire wall. The one closest to the fire wall is the throttle. The one closer to you standing in the front of the car is the cruise control. T It might not have been hooked back up, or tightened right etc.etc..etc... If it lights up in the car as if its working, it shouldnt be a hard fix. I bet they took it off with 20 turns, then put it back with 10!! Could be honest mistake. Could be laziness!!! But, its definitely not a big deal. And they say half the motor to make it sound like a big job. Its part of the intake manifold or what ever the "proper name" is. Its 8 bolts, 5 or 6 electrical connections and 5 or 6 hoses along with the 2 cables ( 1 being remove all the way, one just loosened and push to the back). And an intake hose. So as it isnt half the motor, there is quite a few things that have to be taken out,off or apart to get to plugs 1, 3, 5 i believe off top!! Good luck!! Nothing to stress!!! As far as the light coming on, there could be someting with the timing. It might be barely off where you dont notice it, but the computer does. Take it to the dealer and have the code read, and get an exact reason why. Thats your best bet. Then bring it to a place of your choice. Dealers might be a little more money, but the warranty is sometimes worth it. If that place just shuts your light off and shakes your hand, I'd stay away from them. Something they dont wanna do it might half ass it on you!!