I have a 1992 F-250 with a 351 Windsor. The previous owner removed the cats from the exhaust and there are two tubes that were plumbed into the stock exhaust for the emissions crap that are now just open to the world.. I'm assuming these are for the exhaust recirculation system. Now every time I step on the throttle there is a really loud rush of air coming from one of the tubes and it is driving me insane. My question is how could I eliminate these tubes without effecting how my engine performs? Or could I possibly just plug the one tube or will it damage something.
Thanks

 

The best solution is to follow these tubes backwords and remove everything they are attached to. This is the air injection system and it's seperate from the EGR system so it can be completely removed without setting codes or affecting the way the motor runs. The system consists of an air pump, a pair of valves, an intake filter and exhaust muffler on the passenger frender, and a bunch of rubber and steel tubing connecting it all. The valves are operated by solenoids over by the coil via vacuum lines, the solenoids must remain electrically connected. When removing this you can't leave any vacuum lines open or any holes in the exhaust system upstream of the O2 sensor or you will have problems. Sound like fun?

 

Conanski, I had the CAT removed on my yesterday and I did not have any air tubes that ran do there, I know the Aitr Injection system is till there, Where would mine hook up, I am assuming the back of the heads ?

 

Ford produced at least 3 different variations on the air injection system on the 5.8 EFI motors alone.. why is anybodys guess. You could have a tube at the back of the motor, you'll have to look and see. You should also have a tube down to the cats, maybe part of this has been removed already.

 

Thanks for the help, sounds like I've got a couple hours of work to do today. Good thing we've got a heat wave here today, it's a whopping 12 degrees. Oh well bring on the cold fingertips