I hope this post gets attention here and I'm sorry if there's a better place to ask this!

It might sound silly to some, but I'm curious if anyone has any photos of where they have their wideband sensor plugged into? I mean, where on your exhaust was an O2 bung welded on for a wideband O2? I know I want to put it further downstream than the factory O2 sensors, but before the final muffler(s), right? Does it really matter where or what pipe you use, since we have 2 different pipes to choose from?

Thanks in advance

 

At least 24 inches from the exhaust ports and before any h or x pipe. Also before the cat(s).

 

With a cheap wireless OBD scanner and a good OBD app (Torque Pro, OBD Fusion) you can display your air/fuel ratio for each bank.
No need to buy a gauge and spend a few hours to install it.

 

Are the stock sensors wide band or narrow band? If they are narrow band then monitoring them is as useless as a light show.

 

In my post I mentioned air/fuel ratio, and that is what I meant. You don't get that from a narrow band O2 sensor.
Starting in 2007, the G uses a wide band (aka air/fuel sensor) pre-cat. Post cat are the narrow band.

Check it out and see

 

The two (2) upstream/ "pre-cat" sensors are A/F sensors (wideband) while the two (2) downstream/ "post-cat" sensors are (lowband) O²'s.

So, yes, our G' have both.
Once again SonicVQ beat me to the punch!

 

You do get an air fuel ratio from narrow band. It's just crap compared to a wideband.

 

That's my new year resolution
99% of the time when I see a good question, you have replied in great details, or with an image os the FSM.

 

I don't know of a single production vehicle that comes from the factory with a wideband O2 installed. Maybe someone will correct me but the point is they're rare to non-existent lol. You'd think some performance car maybe would come stock with a wideband. But no. And the wideband is way more beneficial.

 

When you say "exhaust ports"... do we correctly assume you mean the muffler tips?

If before the H/X pipe, how and where? I imagine I'd want to put it somewhere that will accurately capture both banks of exhaust flow and not just one side vs the other...

 

Interesting... My understanding in years past was always that you would want to put an aftermarket wideband post cat(s) (and turbo if you have one) but pre-muffler(s).

Though keep in mind I've had many past vehicles tuned on a dyno or street by a pro and they'll stick a long probe thing up your tailpipe/muffler so they can get an accurate wideband AFR reading... so I'm not sure how the pre-cat sensors work.

Sigh, I still don't know where I should ask the shop to weld in an O2 bung for me...

 

I know the 8th gen Civic Si's had wideband from the factory. My cousin had one and with FlashPro you can monitor the factory wideband in the dash.

 

Everything you need to know about these engines is in the service manual...Section EC (Engine Control). Snippets from same:



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The G has had wide band / air fuel sensors since 2007.
In fact most cars made in the last 10-15 years have them, as the ECU needs more detailed information to meet newer emission standards.

 

I stand corrected as I imagined might happen! And funny timing having this conversation right now as I finally relax after a weekend of wrestling with my exhaust system. I had a rattle somewhere, suspected y-pipe. All stock OEM exhaust. So I figured what the hell, I'll swap my cats out to "test pipes" along with an aftermarket/upgraded y-pipe. I am just a weekend-warrior mechanic but jesus christ that was frustrating as hell. Half the frustration is the brilliant design of some of the "ease of access" options i.e. the notorious "demon bolt". And there's two of every single issue you encounter. Double fun! I completely went through my stash of angle grinder & Sawzall blades. Luckily I didn't break any sockets. I tried a new trick on the rust that actually did something: CLR. Yes, the **** from your kitchen or bathroom. Be healthy soaking rusted parts as best and as long as you can with that ****. Along with PB-Blaster and some Seafoam Deep Creep soaking, the bolts that I did decide to try to remove the normal way came out with lots of patience. I ended up frustrated as hell with where the y-pipe flanges 2-into-1 right before the factory resonator split. Actually, now that I had to cut the damn thing off there, I can see there's a split chamber that runs down the middle of some of the factory exhaust runs.. I actually wondered/cared for the first time to specifically see the insides of the aftermarket exhaust options for our cars. A lot of the photos are just exterior and/or "hey look at this newly installed exhaust system". I imagine if the insides are smoothed out, the exhaust flows better, duh. But how fancy are we really talking here? This doesn't need the intake manifold throttle body port/polish treatment but still. Anyway last word on the struggles: I know it's not an apples - apples comparison, but I upgraded the entire exhaust system on my 05 Subaru WRX from the headers back. I can't remember ever contemplating the meaning of my existence so thoroughly in agony over that exhausting job. Ha. Ha.

I digress.

I love that post with the photo diagram and description. Looks like straight from the horse's mouth on that issue. Again, I'm retarded, but I still am confused or lost as to how sophisticated this factory arrangement is and its integration with the factory ECU & tune. Now I'm getting curious about tuning the vehicle even more. I've played around tuning a few fun money-pit cars in the past, I picked up on the basics, but mostly for turbo or supercharged vehicles. I would always run a separate, independent aftermarket quality wideband i.e. AEM. So I'm wondering if it's a total waste of money then that I want to weld another O2 bung and run a separate wideband now. Shucks. lol

My only last thought is that it looks like obviously, the first upstream O2 sensors are pre-cat. Since my cats are in off and in the garage, I will double-check where the O2 bung sits relative to the cat, but from the diagram, it almost looks like they sorta sit in the middle of the actual catalytic converter material section of the pipe. I could be wrong again but hey. My thought or justification for running a separate wideband is that it'll be truly further downstream post-cat to perhaps give some additional feedback on the quality of the AFR readings? So the factory wideband sensors are like calibrated / Lambda 14.7 blah blah blah? I could just be talking out my a** right now lol I am loopy from lack of sleep big time. Now I gotta drive my ghetto temp rigged exhaust system half put together held up with zip ties to the closest exhaust shop tomorrow and see how much they are going to rape me for a very simple service: weld or replace/weld the y-pipe flange to the factory exhaust so that it can be mated up to the new y-pipe correctly. And while you're at it, please weld a new, separate O2 bung so I can place a wideband O2 sensor (Bosch) there and run it to a gauge in the cabin. Or wait, on second thought, let me ask my forum guys... lol lol

buenas noches senoritas