I need to run the car in open loop, no o2 sensors. If i unhook the MAF will it do this, or do i have to unplug the o2's themseleves??

Thanks
Brian

 

If ive read your question correctly your o2's are already unplugged?. If so then your already running open loop. But if your asking if you unhook the o2's or the maf unplugging either one will put the car in open loop. Unpluggign the maf essentially makes the car run speed density.

 

yeah you answered my question, thanks. I just wanted to know if I unplug the MAF only would it go in closed loop.


Brian

 

If you unplug the maf while running, the car will die.

 

No it won't. At least not on everyones car i know mine wont and several other guys cars wont. I believe if you unplug the maf your car will still use the O2's. The car goes into speed density mode which relies on the O2's.

 

I guess my lt1 is different. I unplugged it once while running and it died.

 

Do you really need o2's?

 

If you want you car to run in closed loop you do. If you want half way decent gas mileage you do. In other words keep them plugged in.

 

I have a 96. I've unplugged the MAF while running, SES goes off car still runs.

Seems like I'm getting 2 answers here, maybe I'll just unplug both o2's and MAF to get it to speed density. I don't want the car to use 02's.

Brian

 

Well my question is without the o2 sensors will power suffer? With the right tuning which setup would make more or less power?

 

The day you tune it in open loop, it will make good power, assuming you get a good tune. The minute something changes - intake, exhaust, etc, the tune will be "off". Back to the dyno for another tuning session. The O2 sensors promote adaptive learning.... the ability to try and control the A/F ratio in response to changes. Delete the O2 sensors and you delete the learning. Have an upset that cuases it to run lean or rich (e.g. - change in fuel pressure) and you can run rich enough to foul the plugs or wash down the cylinder walls with fuel, or lean enough to detonate and damage the internals.

The "learning" isn't perfect, but it does help accomodate change, and prevent problems.

I run open loop, speed-density, but the tune is backed up by more than 40 engine and chassis dyno pulls, and my engine only operates under very specific conditions, nothing is ever changed without checking the tune on a dyno, and the fuel is controlled by taking it out of a drum that I keep in my shed. Not a daily driver, obviously.