This is my down pipe...it has 4 O2 bungs and I am currently running my stock O2 at the very end. I want to tune with the cutout open but run it closed when its not at the track. This is not my daily driver and its mostly a track car. What should I do sensor wise? I can currently open the cutout to where my O2 receives no exhaust, but it still seems to run fine??
Should I run two O2 sensors...one in the cutout and one in the downpipe?
Run just one O2 in the downpipe?
Run just one O2 in the cutout?

 

Since you gave no information about your EMS i'm just going to say run no o2 in the cutout.

and if you're more worried about watching afrs than closed loop run the wideband closest to the turbo even though thast a BAD place for it heat wise.

 

Well currently it is on Crome. I can get away with tunning it out of the cutout and leaving the O2 sensor at the end of the downpipe?? I am just trying to get out of having 2 different tunes and 2 different chips to mess with.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by portenio78 &raquo;</TD></TR><TR><TD CLASS="quote">Well currently it is on Crome. I can get away with tunning it out of the cutout and leaving the O2 sensor at the end of the downpipe?? I am just trying to get out of having 2 different tunes and 2 different chips to mess with. </TD></TR></TABLE>
so solve your problem...tune it open dp...and when its closed youll run a tad richer...end of story

 

So it will be ok to tune with a wideband in my cutout and leave my O2 in the back of the downpipe...and when done,pull out wideband, and all should be good?

 

you will never fully close off you exhaust from getting to the O2 sensor at the end, i had a very similar set up and still had a reading at the O2 in the end of the DP

 

ah i kinda misunderstood you...whateva wideband your using to tune...run that about 6-10" before the exit of the cutout....and remove any other o2 sensors in the system....you dont want to foul them...tune the car's a/f's w/ the cutout open....then once it's tuned you can just remove it unless you want the added safety of having it....id personally run it one a open dp tune....and run it in closed loop w/ the o2 sensor installed in the stock exh portion of the dp...so itll get some correction when its closed dp

 

Wont I need my stock o2 in at least so to not throw a code? The wide band will not be connected to my ecu, it will be what ever the dyno place provides. I dont care about partial throttle at all and it would be cool if I could leave my stock o2 at the end of the downpipe and wide band tune off the cutout and call it a day. I was just worried about my stock O2 throwing things off, but I guess at WOT it doen not matter right?

 

run closedloop disabled when tuning....and remove the stock sensor...then once its tuned well in closed loop disabled....you can even run in closed loop w/ the stock o2...buyt if your tuner is anything decent you should be able to drive you car in closed looped disabled all the time and ditch the stock o2 sensor all together

 

thanks bro