I was curious if you can tune without an o2 sensor.. I recently fabbed up a turbo up pipe out my hood and was wondering if an o2 is necessary for proper tuning. Ive seen tuners put a sensor in the exhaust but not sure. I will be tuning on neptune, thanks for you input.

 

Yes it is necessary for tuning.

You don't necessarily need to weld on a bung for it if you don't plan to run a wideband o2 gauge all the time, or enable closed loop. Your tuner can just clamp a sensor in the end of the up pipe for tuning purposes.

 

^^ +1 here. Needed for tuning and closed loop.
What I will add is that a wideband is crucial for making sure you're golden. Even though you may take your car in to tune, the weather will change and so will your engine's needs. You'll need to make a few adjustments at some point and that wideband will be a critical part in making those.

 

I would tend to agree. I will never run a turbo car without a wideband gauge.

Some people do go without them, and I suppose if your tuner is really good, and you don't intend to drive your car for that long then maybe it's not necessary. But things can always go wrong, and a wideband will tell you so before you destroy your engine.

 

I guess I'm one of those schmucks that don't use one when not tuning.. The only thing one can do is hopefully shut the engine down, or remain in a panic at all times.. I refuse to be victim to that when I have the utmost confidence in my tuner

 

That's very, VERY brave!

 

 

15 years and counting.. 35 events. Same block, one cylinder head due to oil starvation at Lime Rock.

I trust my tuner without question

 

But mechanical issues may not vary the air/fuel mixture. The only mechanical issues from abuse I've had over the years ..none were a/f related, and nothing the gauge nor sensor could have helped prevent

 

If what you're claiming is true, and I don't believe you're into telling tall tales; the idea of running no O2 sensor tells me you're always in open loop, stay around the same altitude, and weather changes are not incredibly drastic..

 

You absolutely do not need one to tune but it does help greatly with the tuning process. I have been around a lot of old school muscle guys and all they had to go by back in the day was pulling and checking the plugs after pulls. You would be amazed at how much a spark plug can actually tell you. Though I can't say I would recommend that approach on a more modern turbo vehicle where there are a few more variables.

 

 

I'm in Michigan. Home of the constant weather change. Although I don't drive it in the winter, I have driven in both sub-40 degree ave 90-degree days. Running on Power FC didn't require a wideband 02. It can be bypassed

The mechanical issues listed are true by 2X0 are true. All can only be salvaged at moment of truth by shutting the engine down only.

Now, a wideband 02 IS needed for tuning. But once done, I never used it. It belonged to the tuner. There is a wideband 02 bung on my downpipe, but there is a plug for after the tune.

 

 

+1 here also. This is how it was determined I had bad injectors WHILE I was tuning.. Inconsistent readings during the same conditions with the same parameters. It didn't come to light though until I reached a point where I felt we pulled too much fuel. We ran the last file that felt best and my AFR was not even close to where it read the first run. I then ran the 2 previous and they were also off. By a lot..
Anyhow. Wonder if the tuner didn't catch this? If this wasn't anything I'd monitor after tuning, I'd probably be in deep **** currently. I still record AT LEAST 1 log a week to ensure I'm on the up and up. A fella can trust his tuner with their life, but that doesn't mean that tune will prevent parts from failing. If that were the case, parts would never fail from the factory.

 

I think we can come to the same conclusion. But I will say in my defense that 1) I have my injectors checked and flow tested before even installing, and the tuner checked millisecond dead times during the tuning.
2) No one around H-T runs EGT gauges (Pyrometers) like I do. I've found a LOT information regarding my injectors from reading that gauge even more than the AFR. 3) I'm sorry. I want to DRIVE my car, not MONITOR my car. If I can't trust my work, my tuner and the turbocharger I have, what the hell is the point of doing this? I see why many here give up on projects after a while, because they can't enjoy the car, because they're so busy worrying about this or that. If you don't know how to read these gauges, then that should be first and foremost. Understand why these gauges are important.

Well, that's my $.10 , anyway. So. Yeah, I'm a Maverick. I don't run an AFR gauge in my daily driver (which is also factory turbocharged) . I don't see anyone complaining about that, is there a crime committed there, too?

 

 

I'm like you. Once it's dialed in I done. I don't have to check anything. Keep my maintenance schedule up to par and I'm good. That's why I don't worry about that after the tune is done My boost controller has already accounted for the changes and I'm good. The only other monitoring I do is my Meth Injection kit, and that's an indicator for the pressure. That's it.

I couldn't imagine the insanity I'd go through with a cooling fan indicator light.. That would drive me insane. My fans are very powerful and I can just hear them based upon the temp reading in my Power FC monitor.

 

Haha! No man, I'm not giving you much of a hard time on your choice. I'm not bashing you for it anyways. I'm kinda shocked that you, of all people, take a "set it and forget it" stance on a performance modified setup. You've set the impression with me over time that you look for the best and give it the best. I could only dream about having somebody available to me that's so dead-on accurate in what they do that I could just say, "meh, it's good and I can look the other way." Maybe I'm just lacking trust and not resources? You know I have the tendency to worry! Odd enough; everyone around me will tell you I'm the most laid back guy they've ever met. LOL! Do I still have fun driving what I built? Absolutely! But I've also set the expectation that there's more I need to keep an eye on too. Maybe since I'm expecting it, it doesn't strike me as excessive, unneeded stress?