i switched to open loop with my scanner while i built a tune for my truck and i have got it pretty good. Now when i switch it back to closed loop it stumbles and jerks and runs like crap and the A/F is all over. When i switch back to open loop it is smooth and runs good. I have new 02 sensors. I mounted the 02 sensors in the downpipe after the turbo, could this throw it off? Or could i be missing something with the tune? Oh and it is 2 bar SD, mods in sig, Thanks!

 

I put your sig in the body of your post for posterity. I have no idea, turbo plumbing confuses the heck out of me and gives me a headache trying to figure out which comes first, the power from the turbo or the exhaust
One of the resident tooba experts will be along shortly.

 

Now, I think that you have to tune the MAF to play nice with your tuned VE table and IFR if you changed that.

Check out the sticky at the top of this section....VE Tuning, it has a method to tune the MAF.

O2s will mess with the tune some depending on placement but I am not sure if they are causing you any grief or not as I have a rear mount and mine are in the stock location. Maybe KB will see this and let you what he suggests for O2 placement. He is SD I think but should know how to deal with O2s in a front mount system.

 

i don't have a MAF, or are you saying i still need to change the tables anyway?

 

you dont have a maf, are your maf tables all zero'd out?

 

the placement of your 02s sounds like the issues. my 2 02s are .....one is in the crossover like in the stock driverside location the other is in the Log manifold on the passengerside. teh WO2 is only one in downpipe.

 

Sorry about misleading! I did not realize that CLSD does not use the MAF. I am about to try it myself so I better wake up a little....LOL.

Good luck getting it sorted out.

 

i can't remember, i'll check.

Will open loop still adjust for temperature and stuff? Is it possible to just run off the wideband?

 

my truck runs souly off the wideband. its to the point the tune is good enough to not need the laptop in truck anymore. to answer your question no, the truck in OLSD will not adjust for temps

 

Why would you want to go back to CLSD if you don't have a MAF?
I'm just running OLSD with no MAF and have no issues.