I've got a 351w in my 1993 bronco, and i've got an exhaust somewhere, near the engine, and it's not REALLY bad, but i can hear it. I'm somewhat interested in finding out if i can remove any of the thermactor AIR setup, where it feeds air into the back of heads. what can i remove without problems, and CHEAPLY, i might add, as i am a poor college kid (at least i'm recently getting a consistent gas mileage number of over 16MPG)? maybe i can increase my MPG more if i remove some of that crap. You guys that have headers, this stuff doesn't even hook up at all does it?

thank you for any insight
Gary

 

Youre getting 16 consistently? What is your driving style? Have you added anything to this truck, headers, chip, etc...?


Rich

 

i have gotten over 16MPG on the last 3 tanks or so, windows down, highway driving between 70-75 about half the time, and city driving the other half, occasionally i have it to the floor to pass someone or to get on the freeway. normally i try to accelerate with it shifting at or not much higher than 2000 rpm. ALWAYS driving slowly when the engine is cold, where it really sucks gas.

what i have done: hypertech coil, ford racing rotor, cap, and wires, bosch platinum plugs. removed 2nd cat, and ran 2.5"pipe back through a 40 series flowmaster and stock tailpipe. advanced base ignition timing about 4 degrees, and run on 89 octane with NO PINGING at WOT. I keep the intake clean by using mopar TB cleaner every few oil changes or so. i have 31" BFG AT's, running around 44PSI, and new brakes all the way around, no dragging. that's about all the performance stuff i can think of at this time, oh, and all of this with a stock paper filter replaced every 9 months or so (3 more months to go).

 

oh man, i left a word out, i meant to say i have an exhaust LEAK!

 

If any of the AIR injection check valves are broken or cracked you will hear an exhaust leak. I believe on your 93 there are two...one in the cross-over tube between the left and right cylinder heads and one in the hose going down to the catalytic converter just below the diverter valve. Check the emissions tag under the hood. All these components should be labeled there.

My 92 had the one in the cross-over tube snap in half and the hot exhaust escaping upward melted a section of the wiring harness that runs across the top of the cowl. Sounded like a typical exhaust leak too.

And NO, headers will not necessitate the removal of ANY of the AIR injection system. The initial injection is directly into the heads so no fittings in the manifolds are needed so none are needed in headers for the same application. The only other AIR injection point is into the cat. Long headers that will not bolt directly to the stock Y-pipe will require relocating the injection tube into the catalytic cnverter if the cat. does not remain in the stock location.

The Bassani System under my 92 has short headers and a stainless exhaust system that keeps the air injection and O2 sensor locations in the system at the stock mounting positions. All of the emissions equipment is in place and functioning. including the entire AIR system.