Installing Wideband O2 sensor

[dayofpain]

d

[MikeSTI]

Originally Posted by dayofpain

Back to the basics.

1. Have you ever installed a wideband in a car?

2. where did you put it?

3. was it the right place?


4. I have done 3, and ALL are still working to this today.

there is my contribution

1. No
2. I would put it in a location that would not exceed 1300 degrees (I personaly dont think the bung at the top of the Downpipe would be below 1300 degrees)
3. It might be an ok place to put it, but are the readings correct? at WOT and 1600 degrees the readings can become false. Sure the mechanics still work but at what accuracy?
4. What do you consider working? The parts aren't destroyed yet so that makes it working? How about accuracy, do the readings match readings done when first installed, or has there been a little data lost due to wear on the device?

[MikeSTI]

Originally Posted by Dean

Moderators please delete this thread or edit for TECH content only!!!

It is clear to me that people are more concerned with being "right" and/or getting their panties in a bunch when someone disagrees than offering real technical data and constructive discussion.

I was trying to help....... I hope!

[Dean]

Phil, Scott, Mike, Ryan I appreciate the constructive portions of your input, I really do.

Thanks.

[Nick Koan]

Originally Posted by Dean

I give up. As the originator of this thread, I am no longer going to read it. Phil, Scott, Mike I appreciate the constructive portions of your input, I really do.

Thanks.

Dean, the threads have been split. This thread can hopefully continue in a more rational manner.

[dayofpain]

i have never seen anyone install a wideband "bare" without the washer. everytime i have seen one go in that i didnt install they used a copper washer. which the video is calling a heatsink. very loosely i might add. if you use the bung provided just be sure to use a copper washer and you should be just fine.

also be sure to avoid touching the sensor and all other noobs mistakes like using lube on the threads. do all that. you be jjusssssst fine.

[MikeSTI]

I'm sure you are correct and that with a heat sink (copper washer) everything will be fine.

Dean, if you are a little consernd about temps, maybe install a EGT in there first to get temp readings

[Dean]

Originally Posted by MikeSTI

I'm sure you are correct and that with a heat sink (copper washer) everything will be fine.

Dean, if you are a little consernd about temps, maybe install a EGT in there first to get temp readings

I have an aftermarket EGT in the header of cylinder 3, and I get readings over 1400 on occasion. Not sure it is worth moving, and I think I have the bung after the turbo which should be fairly safe. If the EGT starts to get near 15-1600, I may get worried. I'll have to take a look further down the exhaust to see if I have a bung already if needed. The LC-1 kit comes with an extra bung, so I can get that welded in if needed.

[dayofpain]

yeah i believe post turbo temps should be alot cooler than 1200 degress. my guess would be closer to 1000.

also if the egt is getting close to 1500-1600 u need to be worried about other things than that sensor. like melting down your pistons.

[Dean]

Originally Posted by dayofpain

yeah i believe post turbo temps should be alot cooler than 1200 degress. my guess would be closer to 1000.

also if the egt is getting close to 1500-1600 u need to be worried about other things than that sensor. like melting down your pistons.

That is why it is in the header on Cylinder 3 and not in the up-pipe. As I understand #3 is the one that is most likely to run lean.

I'm still researching before doing any tuning, and as with everything, there are disputes over max EGTs, but everyone's sensor is in different places.... I think A/F is more important overall, EGT on 3 is a backup watch point, most likely if I get near 100% injector duty which is unlikely on the stock turbo in it's efficiency range.

[dayofpain]

Originally Posted by Dean

That is why it is in the header on Cylinder 3 and not in the up-pipe. As I understand #3 is the one that is most likely to run lean.

I'm still researching before doing any tuning, and as with everything, there are disputes over max EGTs, but everyone's sensor is in different places.... I think A/F is more important overall, EGT on 3 is a backup watch point, most likely if I get near 100% injector duty which is unlikely on the stock turbo in it's efficiency range.

100% correct. most temps taken @ cyl 3 are 1400-1450 MAX 1500 and you want to worry.

most people see around 1200 in the uppipe which would mean at least 100-200 degrees cooler after the turbo.

that would support the 1000 temp range in the downpipe.

[cody]

Not sure if this has been mentioned, but I've read you don't want to install a wideband upside down. Baically, no lower than a 3 o'clock or 9 o'clock position. It sounds like this sensor doesn't heat itself so I'd say you'd want it between 6" and 18" from the turbo in the DP.

[Kevin M]

How is that? The electrons can't overcome gravity or something? I would go with not allowing it to point down so a random piece of road debris doesn't snap it off...

[cody]

To be honest, I've wondered the same thing myself. I've seen it mentioned once on Nasioc and once on wrxfanatics. Take it with a grain of salt.

[Nick Koan]

Both sites are, of course, wonderful sources of accurate and correct information

[cody]

Yah, yah.

I'm thinking BAN SUVS is probably right about avoiding road debris.

[MikeSTI]

and water condinsation

[Dean]

OK, all WB 02s I am aware of for our applications are heated. As I understand, heating ensures the sensor is in it's operating temperature range as well as cleaning the sensor of deposits.

And as I understand, the reson for having it at or near 12:00 o'clock is so crap is less likely to build up on/in it in the exhaust, as well as fall off/out when/if it lands on the sensor. The external portion of the sensor is fairly well insulated from pretty much anything, I think. It should be in my hands tomorrow, so I may know more then.

[dayofpain]

Originally Posted by MikeSTI

and water condinsation

thats Exactly why.

[Nick Koan]

Originally Posted by cody

Yah, yah.

I'm thinking BAN SUVS is probably right about avoiding road debris.

Nah, just joking around. They are both fine resources. There is a lot of crap (like most of the internet) that you have to wade through. And honestly, I don't know if the info you posted is wrong, or right, I just don't know. I'm willing to take everyone elses answers here, though. Debris and/or water condensation sounds very plausible.

[cody]

I asked the guy on WRXF and he also says it's to avoid moisture damage.

Soooo +1

[Dean]

External moisture damage, or internal. Sorry, maybe I'm confused because of the mention of road debris.

I can't imagine the external portion of the sensor being anything but sealed. My assumption was that it is the tip of the sensor inside the exhaust that is the issue since exhaust is clearly not clean, especially before the cats, and does include quite a bit of moisture and particles as products of combustion.

[cody]

Internal moisture is the major potential issue I'd think, but external could be an issue too. You don't want your bung or sensor to sit in water or condensation.

[sybir]

The last thing I want is my bung sitting in water or condensation.....

But yes, it's internal condensation. You're already introducing a condensation point, for lack of a better term, with any irregularity in a smooth tube; making sure water doesn't pool when the car is not running and corroding the sensor would seem to me to be the most important goal. It's all going to burn off once the car warms up, but a low spot with external welds means you have pockets for water to sit in and rust/corrode out.

I'm not going to pretend to be an authority on placement, but the DP/midpipe, depending on packaging, is going to be your best bet. The usable life of the O2 sensor is going to be limited by contaminants more than heat in that spot anyways. Even a tailpipe mount (which isn't claimed to be superior, just a much better option than no wideband at all) that doesn't require permanent mods, and is all the way at the end of the exhaust stream, still gets gunked up and wears out after XXX miles.

It comes down to the optimal location, and then the location that gives you more than acceptable results when incorporated with other logging and gauge readings. Unless you're tuning a car to the bleeding edge, using a tailpipe clamp is going to let you keep an eye on AFR's in concert with all of the other information you're gathering to monitor the engine for a good, solid, daily-driven tune.

[Kevin M]

Water condensation makes perfect sense, since 5-8 gallons of water passes through your exhaust with every tank. Probably not a huge concern, but one of those "why take chances" things.