Thread: wideband 02 sensor

were should the bung get welded at on a all motor car and a turbocar?? im kind of confused beceause of the readings im getting. btw i got the bung welded on the down pipe like 2 inches after the flex pipe, this is for my all motor car and i also have a turbo car and on that one i believe its on the same spot but it has a log mani top mount so its basically more further away even tough they both sit in the same spot.

I think the usual choice is about where you have it welded. As long as it's not too close to the turbo, and before the cat (if you have one) you'll be fine. When the gas exits the combustion volume (where it is much cooler) it is for all practical considerations frozen in its concentration, so a few feet of difference in location are almost certainly not going to change your readings at all.

I'm sure you know already since you say you've already got one wideband, but make sure if you can to weld the bung between 10:00 and 2:00 on the pipe to avoid having it in the path of settling residue after the engine is shut off (otherwise it can be broken by thermal stress when the engine is started again and the sensor is hot).

oh ok thank you danja. the reason why i was worried was because it was reading from 13.2 to like 15 at wot with the afc on default mode and if remember correctly isn't 12.8 a decent afr across the rpm band?? i thought i would have to lean it out but it looks like im going to have to richen it. btw this is for my all motor car.

the farther or closer you put the sensor is the leaner or richer your readings will be, i mines like 15in down on the downpipe and i get really good readings, the sensor has to be pretty close to the turbo to get good readings

Are you sure there aren't other factors for your getting different readings? I honestly don't think that 12 inches will make any difference, but I also have no experience with different locations. But think of it this way. The exhaust gas is flowing quick enough that it will pass through those 12 inches in short time, and there would have to be a very large rate of heat transfer out of the gas to change the reading noticeably in such a short time period.

I guess it's possible, but it just seems unlikely to me. Yes, the closer you can get to the port the better, but you also don't want to get the sensor too close because it can be damaged, so it's kind of a toss up haha.

so it should be fine were its at then right?? the uego instructions say about 36 inches away if youre expecting high egts and 18 inches if you're not. on the turbocar its right on the money but on the all motor car its over, i measured it and its like 28 inches. do you guys think thats why its reading so lean or is it just the way nissan tuned the afrs for a de ecu?? again thanks guys for helping me out.

IIRC, my stock DE tune was about the same as yours. I think it jumped down low to around 13-14 when I first hit the gas, and then a split second later it seemed to climb back up closer to stoich.

the way your wideband is going to react is going to be different throughout different peoples setups, you really couldnt compare my readings to yours as the way your car is tuned is the way the air fuel should respond, and the way my air fuel is tuned is the way mine should respond, but as a whole where you locate the sensor it will make a difference in the correct reading, it could be too rich or too lean depending on the location and how far from the turbo it is.

My Wideband O2 sensor is sitting right at where the turbos exhaust goes into the Downpipe for the most accurate readings. The heat hasnt killed my O2 sensor yet!

i was talking about the stock afr without messing with the afc yet. meaning untuned. i obviously know that everyone's tune is different because everybody has different set-ups. btw this is NOT for my turbo car. this is for my N/A with cai hotshot headers 2.5 exhaust and jdm sr.