cats to run?
Laughing Gas
Joined: Apr 2001
Posts: 1,024
Likes: 0
From: Elon, NC
cats to run?
[updated:LAST EDITED ON 29-Aug-02 AT 06:23 PM (EST)]Hey David,
I had the same engine in my truck that you have. I ended up taking the second cat off and putting a single inlet/dual outlet Flowmaster on it. I never saw any difference other than the sound. Very little discernible change in power either way.
Ron
I had the same engine in my truck that you have. I ended up taking the second cat off and putting a single inlet/dual outlet Flowmaster on it. I never saw any difference other than the sound. Very little discernible change in power either way.
Ron
Moderator
Joined: Jan 2001
Posts: 56,977
Likes: 2,733
From: Virginia
cats to run?
Having enough backpressure is a problem for certain fuel injection set-ups. But I haven't heard of Ford using that set-up on trucks. It has to do with the EGR system.
In the old days, the egr was mostly on or off. Now with computer controls, they try to meter or throttle the amount of egr. One way is with a egr valve that has a potientometer(variable resistor) on top of it. This gives feedback to the computer to tell it how far open the valve is. This is the system the trucks use the most I think.
The other system uses an egr valve, and there is usually a small exhaust pipe feeding it from the exhaust system. This pipe will have a tee fitting and then a hose going to a pressure sensor. The computer looks at the presssure sensor to see how much the egr valve is open. Very little pressure, and it assumes the valve is open. Higher pressure and it assumes it is shut. This system is the one that has problems if a freeflow exhaust is installed. A high performance exhaust will not develop enough pressure for the sensor to work in the egr system.
In the old days, the egr was mostly on or off. Now with computer controls, they try to meter or throttle the amount of egr. One way is with a egr valve that has a potientometer(variable resistor) on top of it. This gives feedback to the computer to tell it how far open the valve is. This is the system the trucks use the most I think.
The other system uses an egr valve, and there is usually a small exhaust pipe feeding it from the exhaust system. This pipe will have a tee fitting and then a hose going to a pressure sensor. The computer looks at the presssure sensor to see how much the egr valve is open. Very little pressure, and it assumes the valve is open. Higher pressure and it assumes it is shut. This system is the one that has problems if a freeflow exhaust is installed. A high performance exhaust will not develop enough pressure for the sensor to work in the egr system.
