Hey guys here is the problem. i have a race tomorrow and the car is at the track right now. I am having some o2 sensor problems and i was wondering if i unplug the maf will the car go in to open loop and stop reading the o2 sensors the car has been tuned for speed density and here is what the tuner wote a cople months ago about the tune "His car also now has perfect idle and absolutely perfect drivability,fuel trims are within 1% rich across the board, speed density is perfect and now has a perfectly dialed in maff transfer.All this makes for a much better running car.So now if he has a maff failure and needs to run the car he can simply unplug the maff and it will run perfect"

 

Car is SD tuned and has a MAF?


BRB checking my engine for a MAF

 

i am pretty sure if you just disconnect the O2 sensors it will run in open loop.

 

no the car has been tuned with a maff and with out one. my question is if ii unplug the maff will it still read the o2 senors or will it put it in open loop/speed density?

 

It says the cars a 95 and he had a speed density tune put on it

 

sorry i must have misread what you asked before. yes, unplugging the MAF does put the car in speed density mode.

 

is speed denisty mode the same as open loop?

 

no it is not thats why i suggested unplugging the O2s to get the car into open loop

 

well that sucks, the car is tuned for speed density or maf, i dont believe it is tuned to run with out o2 sensors.

 

I would unplug the MAF. The wot tables dont use the 02's anyway, however the 02 do affect them. They will have less of an affect if it is transferring straight from the VE tables to the PE tables because the 02's arent used in open loop, and the VE tables are.

 

Thanks man this is the information i was looking for thanks alot man. i will let you guys know how they day goes and it it worked. on a side not does anyone know how to get ride of a code 63 i have done everything i can thing of.

 

if your car is completely tuned in SD... why are you still running a MAF. SD runs much better IMO, having tuned my car in both MAF and SD modes, SD is crisp as hell, better idle (reversion), I was running 15.2:1 A/F on the freeway for gas mileage, and it got rid of most of the cam surge. Plus you can sell your MAF for 60 bucks

 

63 is your o2 sensor, I think replacing it would fix the problem?

 

Not trying to hijack your thread but are there advantages to having a car sd tuned just wandering i have had some mass air issues and would like to know if i could benefit from a sd tune on my setup i have a 388 with ported lt4 stuff up top and run a solid roller cam and a 200 shot any info would be great

 

what does running open loop mean?

 

It means the elm is not using 02 feedback to determine fueling.

 

My car has been tuned to run with or with out the mass air. it can be ran in SD or with the mass air it makes the exact same horsepower on the dyno nathin (my tuner) tuned it so i could do that.