situation.

replaced O2's 2 weeks ago, but all they had in stock was Bosch crap.

needless to say, the bosch O2's went bad again already, car is now starting to develop the hesitating problem.

normally i would just take the Bosch back and get some AC Delcos when theyre finally in stock.........

but...........im about 1-2 weeks away from installing jethot longtubes without emissions, and removing my AIR, EGR, and O2's, and getting custom PCM programming.


i really dont feel like going through the hassle of dropping the ypipe and exchanging O2's when they are gonna be irrelevant in a week or two.


can i just unplug my O2's and force the car into open loop so i can drive around for the next week without the hesitation problem?

or will it throw codes and not run?

 

your answer is yes

 

from what i understand..........open loop is basically like WOT programming all the time............so i will have worse gas mileage....but the car will run ok?

 

I'm running my 02's unplugged right now until I can get custom programming for the HOT cam kit. I've been running with them unplugged for about 2 months with no problems. My gas mileage went from ~14mpg (highway and city) with stock tuning w/ cam kit to ~24mpg (same driving conditions) with unplugged 02's. Everything feels ok.

 

"Open loop" and "WOT" PCM operation are not really the same. Forcing it to run in open loop (no O2 sensors) isn't going to force it to run like it was at WOT. The PCM will still try and set 14.7:1 stoichiometric A/F ratio at part throttle, and the system will go into power enrichment (PE) mode when you exceed the TPS threshhold, and set a richer PE target A/F ratio.

Where you will see a difference is in the PCM's inability to adapt to the mod's at part throttle/low loads, since there is no feedback from the O2 sensors to tell it if it is getting the A/F ratio correct. As a result, its possible that you ocould get yourself into a "rich" or "lean" condition, and the PCM would not be able to correct it. Run rich and you will foul plugs, suffer from poorer gas mileage and lose power. Run lean, and you will burn plugs, possibly get into detonation problems, and lose power.

Why are you deleting the O2 sensors with the LT's? O2 sensors aren't really "emissions" equipment... they help keep the A/F ratio where it is supposed to be, and keep your engine running healthier.

 

ahhh........got ya...........well from what i understand, no emissions on the headers means no EGR/AIR...........i thought it also meant no O2's. my mistake.

so i will need O2 extenders for the longtubes.


and from what you said, its possibly dangerous to run with them unplugged.

but whats worse.........running them unplugged, or running them malfunctioning and stuttering?

 

I ran my last 94Z28 in open loop mode and it responded well. It's pretty simple...basically consider your car carbureted at that point. I know thats an over simplification but what you essentially do is setup your own fuel tables in lt1edit or tunercat and the computer will follow them. You will need to set your closed loop crossover to some really high temp that the car will never see. I think max is 255 so if you decide to do this, go with that.

 

Glad to see all the '93-'97's still running strong. WAY too many LS1's out there these days...

 

I managed to replace my driver's side O2 but haven't dropped the y to get the passenger side one yet. My car runs pretty much like crap with just the one bad one. I figure that's it anyway. I run open loop when I autocross just so I don't get the hesitation and stuff. I can tell that it doesn't lean out on the highway for sure.