I know I shouldn't put them into the exhaust before the turbo, so the only thing I can think that will work is to put them both in the downpipe. It may sound silly but I hate to have the extra restriction of the 2nd O2 sensor in the DP if I can use just one. Can I splice them together and keep them functional, do I have to mount them both in the DP, or is there another alternative I'm missing?

-Chris

 

Is the snout of an O2 sensor really that much of a restriction though?

 

I'm running my passenger side pre-turbo, and driver's side post-turbo. They don't seem to be affected at low boost levels(7lbs). AFR is fine.

 

i was told pre-turbo O2 is a big no-no.

 

The O2 sensor came "pre-turbo" from the factory on Grand Nationals and T-Types ... Aftermarket race headers for the turbo buicks also locate the o2 before the turbo - my guess is that if there were a problem locating the o2 before the turbo, the TR guys would have found out by now.

 

Their is no problem running them pre-turbo or post turbo. I run them on my GN pre turbo, and on my SS post turbo, as well as my Supra post turbo. The sensor doesn't know where its at in the exhaust...hehe

Jose

 

The same exhaust that comes out of the cylinder heads is the same exhaust that the O2s will read before or after the turbo. It may be a few degrees cooler, but your O2s should be heated so not a problem. I'd go ahead and stick two of them in the DP for ease of tuning and so you don't trip a SES light or anything.