Redneck Z

iTrader: (3)

My tuner want's to delete my front, YES front O2's when I put the longtubes on. He has been doing this for awhile and I've never heard of doing it. My friends think I'm crazy LOL. He's not just some kook either. I believe he even helped design HP tuners. Has anyone done or heard of this? Are there any negatives?

MeentSS02

iTrader: (11)

I've deleted the front O2s on mine...you just have to know what you are doing, because what you set is what you get. FWIW, I've not had any problems daily driving my car with no O2 sensors in place (well, except for my wideband).

12secSS

iTrader: (30)

If he helped design HPTuners, he would know not to delete the front O2s when installing LTs. Who is your tuner? Run as far away from him as possible. I bet Ken would get a kick out of this, I'll have to send him this thread.

horist

only reason to disable the front O2s is if you're running open loop all the time... if he doesn't spend the time to tune your car to run open loop properly fuel economy will go to ****... disabling front O2s for a longtube install doesn't seem like hte best route to me.... deleting the rear yes... but fronts... unless he's taking the time to do a full tune I wouldn't do it (and even then, I'd keep the front O2s unless you have your own tuning software and a wideband)

Redneck Z

iTrader: (3)

So without any front O2's to double check the calibration, would it be possible for your car to run lean for one reason or another and do damage, because the front O2's aren't on to correct for this? It seems like I'd have to data log everytime I drove my car to be safe.

horist

it'd likely result in an extreme rich condition at part throttle (WOT O2s aren't used anyways) ... the decreease in gas mileage would be noticable (as well as overall drivability if it's not specifically tuned for open loop)

Redneck Z

iTrader: (3)

With the deletion and tuning he says it will run better, and not be rich at part throttle. He said deleting the front O2's will prevent the PCM from increasing the LTFT's after he tunes it.

MeentSS02

iTrader: (11)

As long as he knows what he's doing, your car will run just fine and have no issues. It'll take him a while to do it (or it should at least), and you'll be good to go.

Bill Bowling

iTrader: (6)

I do not use my O2's but I spend a lot of time setting up my car to run SD open loop. I also have a WB to monitor my tune.

Bill

MeentSS02

iTrader: (11)

I've spent hours upon hours getting my tune down, and I don't even have any REAL mods.

Redneck Z

iTrader: (3)

I'm beginning to think I might not want to get myself into this. Maybe if I had a wideband and HP tuners....

MeentSS02

iTrader: (11)

It is not a trivial matter...that's for sure.

Redneck Z

iTrader: (3)

Anybody else done this?

98cobrakillata

iTrader: (2)

I would say dont listen to the tuner and keep your front o2s.Buy hptuners and play with you tune, if you have access to monitor your car that would be cool, personally I would not do it but I had a very bad expirence with that tuner, Im sure you heard the story lol.

Bombguy99z28

I blew out my o2s from running leaded gas, I drove around for awhile before fixing them. It ran so freakin rich it would stall pretty much any time I cam to a stop.

Now, if he is going to spend hours upon hours dialing in your **** so you can run a pure open-loop tune, more power to him, but I doubt thats what he is planning on doing

Slowhawk

iTrader: (12)

You ussually just cut the signal wire to keep voltage at .450 volt's.This will keep the car in open loop.When you do this you should really run a wideband and spend time tuning it.I would not recommend this if you want gas mileage ect.
The only time I will tune like that is for drag cars.This is because you can shut off the battery disconnect without affecting the tuning/relearn time or to lock in certain timing /AF's at the strip.
2 years ago open loop tuning was the new FAD to do.Some shops still do it.

MeentSS02

iTrader: (11)

Hmmmmmmmm...I'm not sure how some people are doing their open loop tuning, but my gas mileage hasn't been affected at all. And what is this cutting the signal wire thing to keep it in open loop? EFILive and HPTuners can both do it with the click of a mouse

I do agree with the wideband part though...if you don't have that, you have no business running an open loop tune.

Redneck Z

iTrader: (3)

Well, I'm gonna buy some vette rear O2's today for my longtubes. Thanks for all your responses! I wanted to be able to make a well informed decision, and I think I have.

01TA

iTrader: (7)

Redneck Z, I can tell you have been talking to Keith. He told me the same thing when he saw that I was still running front O2s. The question that I had for him that he had NO ANSWER for was smog. From my understanding you will get two incompletes on the OBD11 scan for the missing O2s, and I wanted to know how this will pass CA smog? He had quite a 'tude about it. Personaly I would talk to Rick at Synergy, I have never heard a bad thing about him ever.

WS6FirebirdTA00

iTrader: (33)

a car will still pass with the o2s out, mine does. i run open loop and i tell you it is almost a must IMO for a cammed car, my car runs so much better. i got vette rear o2s and it didnt help the fueling out at all. idle was so shitty with those o2s