[uhoh]

On the 03 hemi's the cat back system is good for only a few ponies. For those believing there is going to be significnat gains I think you should do some research. My findings indicate the gains are in the 3-5 hp range at WOT. There is local speed shop with an excellent reputation that took an 03 put a few different systems on. Again, they are in the business to make money and flat told me to bag the idea and install CAI and leave it alone. The 04's are different in this regard due to the changes in the exhaust. They say it is worth it to change the system.

The theory that a CAI will only be effective if the exhaust is changed is bunk. Not all systems are created equal. In the old days the cats were very restrictive. Today almost all cats are a honey comb design and flow very well for stock applications. If you have a poor air intake design such as the Dodge then you can see improvement in the flow with an aftermarket system. The 97-03 fords had an excellent intake design but a restrictive muffler. So in this case the opposite is true, a simple filter change and free flowing exhaust made a difference. I tried the intake kit on the ford and lost power.

Anyway this is from the WHAT IT IS WORTH department.