Don B
What happens to the O2 sensors and the FI & ignition mapping when the cats are removed? Do you have to do anything special to keep from getting FI error codes?
The ST doesn't have O2 sensors after the cats like a car does so nothing.
Sent from my ADR6400L using Tapatalk 2
Don B
OK, so the two O2 sensors in the ST exhaust are ahead of the cats - seems reasonable to me for the ECU to monitor the exhaust before it gets to them...
I weighed the left exhaust and it is 12.5 Lb. with the heat shield (I assume 0.2lb for that).
hockeypop200
Hey Devil- thanks for the post. Im at that crossroads myself, have a '10 st13. I agree, think the back pressure is burning the place down, starting at my shins. Please let us know how about the mileage, the toasted legs, and if any computer/fuel injection alarms are being thrown
Zonker
Matt Christian
BUMP.....\
SO, did removing the CAT actually help. I'm considering heat wrapping the headers to make her a bit more comfortable, worked wonderfully on other projects. I also hope removing the two small Bessemer Furnaces (cats) by my heels might help.
Don't get me wrong my ST is slightly uncomfortable, nothing like fun in the sun on an old URAL mid July in Wyoming climbing a 9000 foot summit. Air-heads, my first love. That's my story and I'm sticking to it.
=)
SO, did removing the CAT actually help. I'm considering heat wrapping the headers to make her a bit more comfortable, worked wonderfully on other projects. I also hope removing the two small Bessemer Furnaces (cats) by my heels might help.
Don't get me wrong my ST is slightly uncomfortable, nothing like fun in the sun on an old URAL mid July in Wyoming climbing a 9000 foot summit. Air-heads, my first love. That's my story and I'm sticking to it.
=)
I had the Delkevic mufflers, obviously without cats. Made no difference in heat. The Delkevic are only a touch louder when the baffle is installed, but after a couple years, getting to be an old fart, I wanted to go back to quiet. Installing the original exhaust with cats made the bike run MUCH better. Throttle response smoother, midrange torque better. Possibly the cat-free exhaust might have a bit more on top end but I still have no trouble freely revving to the redline in 1, 2, or 3rd gear, and that's as far as I'm going to go at those rpms.
IMHO opening up the exhaust on the ST1300 is counter productive unless you plan to add fuel with an electronic controller. In retrospect it makes sense now, because the ST1300 is set up pretty lean already, so more intake or exhaust air is only going to make it worse. The O2 sensor should accomodate the change but apparently the mapping is in a tight range.
Fortunately it takes less than an hour to swap the exhaust with no knuckle busting. If you have an open exhaust now and your original is handy, give it a try and see if you get the same results.
IMHO opening up the exhaust on the ST1300 is counter productive unless you plan to add fuel with an electronic controller. In retrospect it makes sense now, because the ST1300 is set up pretty lean already, so more intake or exhaust air is only going to make it worse. The O2 sensor should accomodate the change but apparently the mapping is in a tight range.
Fortunately it takes less than an hour to swap the exhaust with no knuckle busting. If you have an open exhaust now and your original is handy, give it a try and see if you get the same results.
Zonker
Matt Christian
Thanks Don.
I'll take messing with the exhaust off my list of farkels to-do. Having owned Twin V's I've got the loud exhaust hankering out of my system. Nice not having ringing ears after a few hours in the saddle.
Last edited:
ST13Fred
Fred
The F800 is geared tall, first gear included. The hydraulic clutch engages quickly and the bike is easy to stall if some off idle throttle is not added.
I made a very thoughtful observance of the bikes' character before and after 'surgery'.
After removing the CAT, (in the front of the can) the easy to stall problem went away, throttle response was crisper and the bike actually ran quieter until 70 MPH; then it took on a gnarly growl.
CATs have been required for 40 years, IMO are dinosaurs now and are more negative than positive in todays' very lean, complete burning engines.
A CAT severely restricts exhaust flow and in time will close it off completely. When engines got 10-15 MPG, they where needed, but not anymore, w/the computer controlled FI systems of today.
But I don't see them going away in my lifetime.
I made a very thoughtful observance of the bikes' character before and after 'surgery'.
After removing the CAT, (in the front of the can) the easy to stall problem went away, throttle response was crisper and the bike actually ran quieter until 70 MPH; then it took on a gnarly growl.
CATs have been required for 40 years, IMO are dinosaurs now and are more negative than positive in todays' very lean, complete burning engines.
A CAT severely restricts exhaust flow and in time will close it off completely. When engines got 10-15 MPG, they where needed, but not anymore, w/the computer controlled FI systems of today.
But I don't see them going away in my lifetime.
Thanks for the info