I've seen a lot of people reply to posts about sputtering and hesitating by saying its the spark plugs/wires or maybe the cat. I've had both of these replaced and I was wondering if those are the only things that could cause my car to sputter and hesitate when I try to accelerate.

 

Sputtering, as you call it, is actually misfire. Misfire can be due to ignition problems, fuel problems, or mechanical problems.

The ignition problems could be due to spark plugs, plug wires, ignition control module, ignition coils, any wiring problems between the ignition components and the PCM, and sensor problems.

Fuel problems could be caused, by bad injectors (dirty, worn, etc..), bad fuel pressure regulator, bad O2 sensors, weak fuel pump, clogged exhaust, bad sensors, dirty fuel filter, etc..

Mechanical problems include, bad valves, wiped cam lobes, poor compression.

Also you should have the PCM scanned and take care of any codes that may show up.

 

I had the plugs and wires changed about 3 weeks ago. I had the codes checked about a week after and itgave me a misfire on 5and it turned out to be a defective wire. Now its giving me a misfire on 4. During this time I've also had the cat replaced. I was just wondering if it could really be another defective wire or is something else causing the misfire.