WB installation location effect on AFR readings...

[Braemerz28]

I could swear I read something on this once upon a time, but I could find it again. Question is....

If my WB is located farther away from the cylinder heads than the stock O2's, what difference might I expect to see in readings between the two?

Here's what's going on...
4.3 v6 in a GMC Sonoma (S10). I tuned my VE to within 1%, tuned my MAF to within 1%, turned all FT's back on and they are all staying very close to nominal so I'm pretty sure I got the tunes right. However, WB reading is consistently around 14.5 instead of 14.7.

WB is located in the y-pipe downstream of the joining. So, it's about 2-3 feet farther back in the exhaust system than the stock narrow bands. Could the simple location be giving me the 0.2 difference?

If it's a "bogus" difference due to the location, then I'll forget about it. If for some reason my stock 02's are reading 0.2 low, then I'll just up my commanded from 14.7 to 14.9 and be done with it.

Thanks!

[LosLS2]

the farther back you go with the wideband, the leaner the reading will be. I can tell you though that you have it in a good spot. I found that having the wideband further up stream (before the y-pipe) would give very erratic readings. 3 wide open throttle passes would yield 3 different sets of values. The Wideband behind the Y really helps the data be more consistant and gets you a good average of both banks.

I would not worry about being off by .2 average AFR regardless.