forcing car into open loop

[nacho8705]

The information i have seen about forcing the car into open loop has not been very clear. This is for a maft-pro, but this question is about the ecu in general.

Force open loop by:

disconnecting 02 sensor - this throws a code
disconnect 02 signal leaving 02 heater plugged in - no code

What is the best way? some places i have read that disconnecting it completely forces the car into limp mode, causing it to run rich and pull timing.

If just the signal is cut, does it go into open loop with out the limp mode?

Thanks in advance

 

[nacho8705]

no one has any input?

 

[935motorsports]

If you want to use your own tuning device, without the ECU getting involved, leave the stock o2 plugged in and just open (outside of exhaust).

A less ghetto way is to use an o2 sim.

 

[Shaz]

 

[Kai]

....why do you want to force it into open loop?

 

[nacho8705]

....why do you want to force it into open loop?

So that my maft-pro can control idle/non-wot afr ratios without fighting the ecu. It also allows me to use the cruise and lean-burn features. If i leave the o2 hooked up, the ECU and the maft-pro will fight each other and my AFR will bounce all over the place.

The idea is that if the stock ecu is not receiving a signal or does not detect an o2 sensor, it will go into "open loop" and will use pre-determined fuel maps that stay the same no matter what, allowing me to tune.

The question is, is there a diference between unhooking the o2 completely and cutting the signal wire?

 

[wardog]

Just unplugg the o2 sensor and be done with it . Thats what i did with mine and be ready to tune PT, Cruice and all that good stuff with the MAFT PRo. I got an Lc1 to keep track of my AFRs Do you have a WB ?

 

[suprajztwenty]

just to add to the post for future searchers (sorry for the resurrection)

true open loop, you should be reading 0.x amount of voltage from Vf and E1. the only way ive found so far is to use a 2k potentiometer wired in series with the coolant temp sensor (i used a 2.5k cause its all they had) i also have the temp sensor outside of the engine so it will NEVER go out of cold mode...why do it this way? i know you shouldnt want open loop, but using my greddy emanage blue i was unable to tune out a cruise 30% throttle lean spot. the more id tune, the more the tccs would correct and just worsened, the higher the values became.

i got the engine up to temp (180'ish for me) and simply adjusted the potentiometer until i saw 0.5 (this isnt a set in stone voltage, anything 0.x anything is open loop) now ive achieved that i made a few pulls...the ambient air temp from the pulls caused a reading on the temp sensor (removed from engine) and i had to move the knob to its max. now i have it mounted in the car with the knob maybe 1/2 turn (a "little" lower idle) when the car starts cold (coldstart injector unplugged) it idles perfect around 850, the warmer it gets though my idle keeps climbing to about 13-1400. im assuming its something thermal inside the throttle body so im bypassing the coolant lines tomorrow and i should have idle taken care of.

currently i dont know what timing does in open loop, search results dont yield much.