If my wideband is operating any time my car is running with A/F of 12.5 at WOT (N2O car) how long will the sensor last before it has to be replaced. TIA

 

I got about a year out of it, but I have run 100 octane a few times when I ran low at the track so that probably hurt it a bit.

 

one way to shorten the life of any O2 sensor is to have it in the exhaust stream unheated. As long as it's always powered when the engine is running, you should get a normal lifespan.

 

Hey Mike

What do you consider normal life span??

I will be getting HPTuner and mabe a wideband. I think most guys put the wideband in the rear O2 sensor hole (don't hold me to that)...


DH

 

I have a couple of wide band questions also .

If you put the wide band sensor in the rear O2 sensor bung after the CATs, will that effect the reading?

If you just "TEMPORARILY" insert the sensor in the rear exhaust pipe opening, will the wide band provide the correct reading?

Thanks!!

 

Bill, supposedly before cat, after cat, and tailpipe will all read similarly...which baffles most people that before and after the cat it will read the same.

If you're running a wideband "full time" you can replace one of your primary (before cat, upstream) 02's with the wideband and a "piggy back" connector which will emulate a narrowband signal for your ECU. That way the wideband will be on and available (thru the wideband cable that you need to wire up inside the car to a laptop and/or gauge) all the time. If you get an Innovate LC-1, you can use the fairly inexpensive VW wideband connectors if they ever go bad ($70 or less, like a normal sensor for our C5's). Ping me if you want me to explain more.

 

I totally disagree. There's not a wideband system provider that doesn't caution against installing after the cats. There's no harm to the sensor, but the readings will be skewed.

Sure; many sell a tailpipe holder for the sensor, but this is specifically for use with cars that have no cats at all.

For a C5, that means running the sensor upstream from all the cats. SO for those with pup-cats as well, in front of them too !

no.

some Volkswagons come with WB sensors from the factory; and they last just as long as NB sensors (or so I've read). The big enemy of any O2 sensor is seeing exhaust - but not being powered (so the internal heater will operate).

Too many will install a WB sensor for tuning; then after the tuning is done - will leave the sensor installed but will disconnect it.
That's a no-no and will seriously shorten the life of the sensor.

I removed my Innovate WB sensor once the tuning was finished. The extra bung I had installed came with a screw-on cap.

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no matter what mfgr wideband system you purchase, they will all tell you this:

 

here's where my bung was installed:



this is underneath on the pass. side - looking slightly rearward and upward. It's a little bit below the preferred position (upright, between the 10:00 and 2:00 position); but I don't leave the sensor installed when finished tuning.

The 10:00 to 2:00 location is suggested - to keep water (from a cold start) from possible getting in the sensor.

 

Mike

Thanks for the pics and GOOD information

Can you or can you not just install the wideband in the front O2 spot and just leave it there. So that it is always heated and always available for tuning.

Will it function ok as a narrow band??

I gotta go look and see where my pup cats are on my Kook headers


DH

 

if you swap out one of the front sensors - and leave the cars PCM connector disconnected to that one sensor, you won't be able to tune as the PCM will quickly throw an error code and the engine will run rough.

There have been attempts to use the wideband sensor in a dual role... both for the WB instrument and providing the cars PCM with proper data. A problem arrises because factory O2 sensors output zero to one volt; wideband sensors output zero to five volts. So some sort of conversion circuitry is needed to scale the wideband sensors voltage range - down to what the PCM can understand.

I tell ya; it was painless, cheap, and quick to have an additional bung installed. If that's your main concern, then don't worry about it.

 

interesting...

http://www.ls1tech.com/forums/showth...7&page=1&pp=10

 

Thanks for the explanation.

I was under the misconception that some O2's were able to do double duty. Yes my main concern is putting a hole in my LT headers. Also I am going to be leaving it in for full time timing availability so it will need to be mounted in the upright position. I also worry about it always getting heated up.


DH

 

Bill and Mike

Thanks for the info! Looks like I will have to remove my header and install a BUNG. Infact, I already have the bung, just got to get my **** in gear!

BC

 

Some O2's are double duty. I can calibrate my LC-1 auxiliary output to match a narrowband (0 to 1 volt) signal to the PCM. You can change the drop off rate and sensitivity so it looks exactly like a narrowband to the ECU.

 

Using rear bung or tailpipe is not more than a few tenths difference.
I have run on dyno with my header PLX logging and tailpipe. It fact it seems to be within normal variation. Have tuned cars using rear after cat bung when they dyno the AFR is as set.
Cats do not remove O2.

 

I am curious, when you have your wbo2 set up to simulate a narrow band. Have you logged both short and long term fuel trims during this? And if you did what did you see on the side where the simulated signal was set? The reason I ask is because I am real skeptical about the accuracy of a simulated signal to the PCM. I say this because as you know the final control element in the closed loop strategy is the o2 sensor, and if its not right it may go lean or rich.

 

This is exactly what I said and people jumped all over me. My results and experience (or lack therof) have showed little or no difference. Furthermore there are TONS of legit tuner shops who shove a sensor in your tailpipe regardless if you have cats.

I understand narrowband operation theory. Jump on any tuner forum with turbo/FI cars where people are monitoring wideband all the time...you'll see that the wideband o2 with the narrowband signal is better than your "true" narrowband. Widebands are more accurate and switch quicker.

 

I'm with Mike on this one. An after cat reading is only a guess. There is so many factors in play that can change the reading, it will only be a guess. For example, a rich low speed with good cats after reading will be huge difference compared to the before reading. Then again same mix at high speed with the same cats will be much closer before and after readings since the cats have much less time to act on (burn off) the extra fuel. Typically, the faster you run the exhaust through the cat the less effective the cat becomes, simply because it has less time to act on the fuel. Then again, if you are running way lean you may not notice hardly any difference between the before and after reading at any speed. So you just can't say will it will always be 2 points off. It may always be close to 2 points off WOT, but it won't be 2 points off over the entire operating range. I agree the before and after reading will be heading in the same direction and you "can" tune a car by that, may work fair for WOT dyno pulls, I'm saying IMHO that is not the best way to try to tune a car.

Another small reason not to run your WB after cat is there will be much more water back there. Shouldn't be a problem as long as you don't power your WB before you start the engine, but you must power the WB as soon as the engine starts.

 

Here is the setup I'm running. I welded two extra bungs right behind the factory LG bungs for my permanently mounted dual LC1's. Note, these are all factory O2 sensors screwed it to make sure everything fit OK, didn't have my WB O2 at the time of the header install.


I also welded two bungs in the lower side of the pipe just in case I ever needed quick access to the pre-cat exhaust. If I pull it on a dyno I can simply screw out one of these bungs and screw in a WB sensor or and adaptor to their sniffer pipe or anything else I may ever need to stick in here like a temp sensor. You should not run O2 sensors at an inverted angle very long, they can build up water in the sensor and damage the sensor. But for a quick check it works great. The plugs are cheap ($1.25 each) import oil drain plugs, even comes with copper gaskets!


I found a box of cheap stainless steel bungs on eBay. I stuck them in the lathe and turned a small 7/8" notch on the back of them. I used a hole saw to cut a 7/8" hole in the pipe, the bung will then fit flush in the pipe making welding easy. I had to weld in my own after cat bung for the factory rear O2 sensor in the X-pipe also. So I did a lot of bung welding, running 6 sensors and have room for two more!

 

[QUOTE=SpeedyZ]Here is the setup I'm running. I welded two extra bungs right behind the factory LG bungs for my permanently mounted dual LC1's. Note, these are all factory O2 sensors screwed it to make sure everything fit OK, didn't have my WB O2 at the time of the header install.


I also welded two bungs in the lower side of the pipe just in case I ever needed quick access to the pre-cat exhaust. If I pull it on a dyno I can simply screw out one of these bungs and screw in a WB sensor or and adaptor to their sniffer pipe or anything else I may ever need to stick in here like a temp sensor. You should not run O2 sensors at an inverted angle very long, they can build up water in the sensor and damage the sensor. But for a quick check it works great. The plugs are cheap ($1.25 each) import oil drain plugs, even comes with copper gaskets!


I found a box of cheap stainless steel bungs on eBay. I stuck them in the lathe and turned a small 7/8" notch on the back of them. I used a hole saw to cut a 7/8" hole in the pipe, the bung will then fit flush in the pipe making welding easy. I had to weld in my own after cat bung for the factory rear O2 sensor in the X-pipe also. So I did a lot of bung welding, running 6 sensors and have room for two more!

Speedy,
You are fully bunged up!
I used the Ebay bung as well, but only a lowly, single.