Question on Catback Exhaust/Headers/ Off-road or Catted X-pipe for 03 Cobra

[390PLUS]

I am planning on doing the exhaust on my new 03 Cobra and have spoke to a few "gurus" around the Michigan area.

Let's first start with the headers:
One reputable shop is telling me that they're not worth it due to the time and money. He equated the addition of 7-8 HP at the wheels.

Another shop disputes that and is going to provide a dyno graph that states otherwise. More info to come on this.

Regarding the cat-back exhaust and the x-pipe. I was told by one shop all I need to do is purchase the in-line resistors that mate to the oxygen sensors to offset the check engine light I would receive. I spoke with an engineer at Ford and he stated that I need to be extremely careful and "tune" the ECU to offset the back-pressure otherwise I could burn out the exhaust ports. What the hell is this guy talking about? This is a first that I have heard of this.

Any information you all can provide would be helpful. Thanks.

 

[mystic1]

I wouldn't thinkg you would need an inline resonator for your setup for backpressure. I think at the worst case you would lose some low end torque, but not run the risk of burn the exhaust port. You will see about a 10-15rwhp gain across the whole entire engine rpm with this setup. It is one of the last mods I would do becuase of cost. There are some advantages to this setup though that your car will be running with less stress due to a extremely free flowing exhaust. Alos you won't make as much boost, but the same amount of power. Which is less strin on the motor.