I hope to soon be adding turbo parts to my 2.8 Grand Prix. I'm looking to run a wideband setup, with a narrow band output for the ecm. Having said this, the Bosch sensor is going to hate the pre-turbine in houseing location. Is it a bad idea to just plug that, and add a new bung in the downpipe, which I have out of the car right now anyway? That way i can run 1 O2 sensor for nb and wb, as well as reduce some of the garbage in front of the turbine. Does this sound logical, or is it necessary to have a narrow band infront of the turbine (seems like an unnecessary restriction to me)?

Thanks,

Jon

Just FYI in case you didn't know, on TGPs, the O2 sensor threads directly into the turbo.  And a tip- don't run Bosch sensors- they  are JUNK.  Run a AC/Delco and you'll be golden.

Yeah, I guess i worded that badly, I know it's in the turbine housing on the inlet side. I was looking to run a wideband setup though, and as far as I knew that pretty much meant it had to be a Bosch. Should I run 2 then? A delco for the ecm, and a bosch for tuning?

I don't know about wideband, but I can vouch that Bosch O2 sensors are crap. I just went through my 3rd one in two years, and switched to AC Delco....Delco by far is best.

What are people using for wideband if bosch is junk? I thought these were commonly used?

Wideband and Narrow band 02 sensors are two completely different animals when it comes to Bosch quality. My dyno runs a Bosch WB and it is still as rock solid as it was when brand new. A little slow to warm up...but damn good. NTK is also another great WB02 manufacturer for reliability and accuracy. I will be replacing my Bosch with an NTK when the Bosch gives up the ghost because it heats up in 5 seconds where as the Bosch will take nearly 30 to come live with my Autronic B-type circuitry.

Kenny, what do you think about removing the sensor in the turbine housing and moving it to the DP? I figured if the sensor can't take the heat, and it's a restriction, why not move it? Any chance it'll help with the restriction on the exhaust side? Will there be problems with accurate readings?

Restriction? Considering the extreme backpressure of the tiny turbine wheel and housing...removing the minimal true solid surface area of an 02 sensor housing would be negligible at best.

Heat for an 02 sensor? Considering my WB02 has seen temps in excess of 1400*F and is still functioning perfectly fine, I do not think our less than 1000*F is going to hurt it any.

Moving the 02 further away from the source of collection will dull it's response. That is why on every header build, turbo install, etc we place the 02 at the closest point of true collection as possible. Also that is normally the hottest point to help it clean itself out of carbon and turn on the fastest with heat transfer from the exhaust. Another issue of moving it further away is the fact that you are opening yourself to possible false readings from exhaust leaks.

Putting the WB02 in the turbo housing and moving the NB02 to the downpipe would be ok or visa versa. But I would not send both down the pipe to a cooler region and with more access to open exhaust leaks. Trust me...you do not need to hear an audible exhaust leak for it to be huge and present enough to throw off an 02 sensor either NB or WB.

Thanks for setting me straight. I was thinking that the O2 couldn't help the situation, but if the turbine is much more of a restriction, probably not a big deal. The temperature thing I was talking about came from PLX. I guess I need to read closer, I thought it said 850F and that's why I was confused. 850C is 1562F so I guess I'm in the clear.

QuoteMount the wideband oxygen sensor before the catalytic converter and at least 24 inches downstream from your engine block or turbo for optimal performance. The sensor element will fail if it is exposed to exhaust gas temperatures above 850 deg Celsius

Sounds like i'll be sticking with the stock location. Thanks for the help.

Jon

Anytime.

If the EGT of our motors are at 850*C many things would be melted internally...so just like a cockroach in a nuclear war...the 02 sensor would be fine.  ;)

I thought the high pressure for the stock O2 sensor location would make a WB sensor read wrong or distroy it over time? I've located mine on the down pipe.