some of u know i was having problems with the stock 1 wire o2 sensors failing on me after only a few days,well today ive burnt up the second heated o2 sensor in 3 months.the motor dosent run exsecivly lean/or rich.no visible smoke etc.but my afr gauge starts to read lean,and the ecm just starts adding fuel with no change in the o2 sensors output,i verified this with a volt meter and an lm-1 wideband,so i know the sensor is bad and not gauge.with the lm-1 im reading an idle afr of 11.0-1 to 13.5-1.the second i replace my o2 with a new one things go back to normal.what can u guys come up with that could be killing my sensors on me,since ive already eliminated the rich/lean conditions,when the sensor works i maintian a 14.0-16.0 afr under light load and cruising,and when in boost i range from 10.5-1 to 12.3-1

 

Is this a turbo motor? Can't quite remember if it is or not, but I"m wanting to say it is. is your sensor before/after the turbo? If it's before the turbo that's bad for them, they don't like pressure and they don't like the heat; if it's after, you may still be having a heat issue. Innovative's LC-1 instructions tell you how to make a heat sink, you get a 4X6 inch piece of copper sheeting and bend it into sort of a "U" shape with a hole in the middle. THen you screw your sensor through that.

 

yeah it is a turbo motor,i have my 3wire o2 sensor in the downpipe about 4 inches from the turbo outlet.

what happens to be a safe heat range for an o2 sensor,i can get the pipes hot and check the temps with a infared heat gun to see if its getting way to hot.Though i dont think heat is the issue,cause if i unhook the power wire to the heater,the o2 wont stay hot enough to get acurate readings at idle,but i quess it is possible for it to be getting really hot at wot/and medium engine loads

 

what do they look like when they come out? Have you had a scan tool on them, normally when they start failing they cycle (go past .450VDC) slower, is it doing that?

 

the output hangs around about .250v,even if i rev the motor,or its idling.everytime i have an o2 sensor go bad it always does the same thing,it just always reads lean.even though the engine is runing rich as hell.

 

Not sure about your motor but, the turbo buicks have thier 02 sensor before the turbo? And the universal 1 wire Denso replacement sensor is hailed as a pretty darn good sensor. You shouldn't need a heated 02 sensor.
What type of gas are you running? Unleaded? Leaded?
What are you using to monitor your motor? What are 02 counts at idle? 02 counts at WOT?
If you wouldn't mind I would love to see some pictures of this beast. -Nick.

 

I would say there is a couple things you can check,

I always use a bit of antiseize, it helps with the ground connection as well as keeps the sensor from seizing.

I know that the sensors don't like excessive heat, and I always hear to place them about a ft. past the turbo outlet, maybe throw another bung further down the pipe. You can get 'em for like 8 bucks, its worth a shot.

are you using alot of silicone sealant for the headers or various gaskets? its possible that they've been poisoned, and might be something that just needs a bit of time to burn off.

check the ground system for the sensor, there should be grounds that need to be tied close to the sensor (like back of cylinder head or intake manifold.)

other than that, not sure what to say......

 

i run pump gas,i dont use anyhting other then an lm-1 wideband to monitor my engine.and that is not permantly installed,i only use it when im having a problem or make fuel system changes,or increase boost level.dont know what my 02 counts are right now i have no way of data loging.With the single wire 02 sensor
in the downpipe it does not get hot enough to read correctly.a picture will explian this better,but its due to the fact that my turbo is mounted infront of the motor,so the o2 sensor is pretty far down the ex stream.

 

heres were my 02 is located u can just see it in the top of the pic


and heres a front engine shot

 

Again, what do they look like when they come out?

Based on everything else you said I’m betting on a pushed head gasket and you’re fouling them with coolant.

 

they just have some carbon buildup on them,i didnt get to take a pic when i replaced this last one,but except for a lil bit of black soot/carbon it looked fine.The black soot was prolly from the motor running rich due to the dead o2 sensor for 2-3 days.i doubt it has a pushed out head gasket it dosent smell like mayple syrup when the cars running,nor do i get any form of smoke out the tailpipes

 

Well, I have one that the only way that you can realy tell for sure is by doing a combustion gas test on the radiator, but if it was coolant fouling you’d have some light colored deposits on the O2.

In that case either you’re doing something really wrong like shorting out the signal wire from the sensor, or you’re silicon fouling it with some non sensor safe sealant or something similar.

 

the only thing i can think of is either the gasket material i used on the turbo outlet,and or the cooper seal.i used some green industrial gasket material on the turbo outlet,with a thin bead of cooper seal just to make sure it sealed up real good,im gonna switch that out for a steel gasket and see what happens

 

I have one non-turbo rig that I used Permatex Ultra Copper on the exhaust flanges at the heads. The Bosch 1-wire O2 sensor is 6 years now and works properly.

Run a bastard file over the outlet flange and don't use the unknown green goo. See if you can get the datasheet on it and find out what the contents are. I like the filed/sanded flat surface setup better. It wouldn't take much time if you welded the downpipe on it without a lot of heat. Or it could be as bad as my turbo manifolds were........030" out at one end. It took about an hour to file and emery cloth each of them to make them flat.

EDIT: Is that a SSAC 46mm wastegate?

 

the gasket stuff is a sheet.like the mr gasket gasket paper,this stuff is just green and a lil thinner but stiffer.my flange was flat when i welded it,but i made it from stianless that was to thin,so the heat from the turbo finally warped it a bit.im gonna machine a new flange soon.

and yes that is an ssac 48 mm wastegate

 

Since it was paper material it is probably fine. I thought it was a type of sealant. Did you check the copper sealant package for "O2 safe"? Pretty much all of it is now.

How is the wastegate holding up? Any sticking? I read a little bit about them over at turbomustangs.com. Some people love them and some hate them due to sticking.

 

ive got over 8k miles on mine and no problems yet