89 GT

[Harndog]

A few months back I picked up an 89 GT Hatch. The PO had built the engine to include e303 cam, crower roller rockers, 58cc ported heads, Car Tech intake with 70mm maf, bbk cai, flowmasters. However he has left on the stock headers and cats. I have not really messed with the newer FI fords. I plan to change out the headers and the h pipe. It has flowmasters but they are welded in between stock pipes.

What type of gains can I expect with this build just from the exhaust? Also I am half embarrassed to ask this but do I have to mess with any o2 sensors when changing the exhaust. I am leaning toward longtubes. Whats the best bang for the buck?

Thanks

 

[BK_CAULEY]

you will have to have 02 extender harness for the longtubes. and you wont feel much gain but there will be some.

if you want to feel a difference get rid of that intake and get an explorer/gt40/cobra style one.

 

[Bullitt347]

you will have to have 02 extender harness for the longtubes. and you wont feel much gain but there will be some.
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I disagree with this statement. I have found up to 20 whp with the upgrade of the exhaust system, even on a basically stock 5.0