Wideband O2 question...placement in exhaust stream

I have a C5 with long tubes, cats, x-pipe, etc. (Supermaxx). I am waiting for my new flashscan stuff, and want to purchase and use a wideband O2. I'm going with the PLX setup, would it be okay to use the existing bung downstream of the (very short, directly downstream of the headers) high flow cats? I had my SS headers coated to reduce heat, and don't want to put a new bung through the coating if I can help it. I was thinking I could either use the wideband for logging and for the PCM (some have been able to make it work fine, I hear), or put in a new bung. Any advice/opinions? Thanks for the help...

For idle tuning I'd put it in front of the Cat.
There's disagreement as to whether the Cat will effect the O2 sensor at idle. Off-idle I don't believe it will effect the O2.
FWIW.

You could replace the front 02 and pull both WB and NB off the PLX Bosch sensor.

thanks, that's probably what I'll do....I don't want to mess up my cermachrome coating.....

huh :?: :?: :?: :?: :?: :?: :?:

I'm with you Dirk. What'd he say??? :lol:

Damn! It's a spambot!!! fawkers.

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Originally Posted by Bruce Melton

You could replace the front 02 and pull both WB and NB off the PLX Bosch sensor.

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That's exactly what I did and it works fine. I've mostly been driving around with a stock tune and have had no problems. I plan to start tuning once V7.2.3 is released.

I went with a separate bung in my passenger header for my PLX WB. At the time, no one had really sorted out the NB emulation too well so I didn't want to chance it. Plus, I played it conservatively and kept the stock NB in in case my WB dies prematurely (After all, I installed it! :lol: ) I also went ahead and put in a temp probe while I was at it. It did minimal damage to the Jet Hot coating. Now, I'd be more tempted to skip the extra bung and go with emulation. Here's a link to my installation.

http://redshift.homestead.com/WBO2.html

Nice header.

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Originally Posted by Patches

http://redshift.homestead.com/WBO2.html

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that's got to be the cleanest install i've seen! Great work!

Where do you install the bung in the exhaust stream if its true dual up to the front of the muffler? That would put the bung between the cats and muffler. If the bung can be placed on either side, it seems this would make an inaccurate reading since you're only getting exhaust output from one side.

Mine is a true dual all the way back and I only installed one on the passenger collector. You could install a wideband in each collector and log them alternately and adjust your VE table using an average of the two but I have found that to be unneccessary as long as both sides are close. After I tuned using the Auto Tune procedure and then recalibrating my MAF, my trims are looking very good - and very consistent - on both sides. I do have a matched set of 30 lb. SVO injectors and I've logged trims quite a bit to ensure this.

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Originally Posted by Patches

...Here's a link to my installation.

http://redshift.homestead.com/WBO2.html

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Sweet write-up! :)