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Wideband sensor placement on a straight piped engine

Understanding AFR

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Good evening ladies and gents.

I had a question. Where do people place their wideband O2 sensor on a turbo car that's got a straight pipe from turbo to a hks backox? (no cats, resonates.)

I've tuned a handful of starlets and most of them have a 2.5 inch straight pipe setup like the one I've described above. The sensor is located exactly where the firewall (guestimating about a meter away from the turbo) is and is at the 2 o'clock position. What I've come to realise is that on such setups the afr readings atpart throttle and idle are unrealistic (22.4 afr at idle) what maybe the issue? The next car I'm tuning has the same setup however it's got the toyosport td04 kit. I plan to install the wideband onto the down pipe right after the turbo only for the tuning process and then relocate it back to the current location. Although, this will mean the car won't be able to run closed loop fueling accurately

i have always fitted within the first 400mm from the turbo i prefer 200-250mm and I wouldn't listen to anyone that tells me I'm wrong on this

regards Ross

Thanks Ross for the information. Does that give you better, consistent and reasonable values ?any impact on the sensor life in your experience?

I'd agree with Ross.

Usually, an excessively lean lambda is due to an air leak - even though it may be under a slight pressure overall, peressure fluctuations and/or venturi affects can draw air into the exhaust.

However, there may be a different cause - different types, and even models, lambda senders have different characteristics and need to be set correctly in the ECU - is it possible you have the wrong type/model of sender selected?

Checked for leaks ,there are none.

Car currently operates is on the stock ECU and the wideband doesn't interact with the ECU yet. Want to wire in the standalone next week