DIYEFI.org Forum

Hello this probably a question more for toalan but I decided to post it here.
Has anyone here used a wideband with pressure correction?
I've seen only a few units on the market with such abilities. I am wondering how much a difference it makes consider that esp with a turbocharged system trying to get readings pre turbo can become pressurized more than atmo or even in say stock exhaust with a turbo system.

The datasheet says that the change in pump current is approx 1.3%/50hpa

To put this figure in a real situation, @ 0.8 lambda, each psi of pressure in the exhaust would make the reading richer by ~ 0.0009 lambda

The problem with metering pre turbo has nothing to do with pressure, it has everything to do with temperature. Oxygen sensors have no means to actively cool itself, and they will just get cooked to death. Also temperature has a 6-7% effect on pump current per 100 degrees kelvin. I know AEM has some system with back pressure compensation and includes some dinky heatsinks for the sensor, the problem with that system is that it does not display sensor temperature, you could be toasting 200 dollars worth of sensors at once and the AEM will not inform you of that.

You'd want the tip of the sensor flush with the inner wall of the pipe to keep it out of direct flow, and also further removed from the pipe. That along with a good heatsink between the sensor body and tube should eliminate overheating, one would hope. If you can provide a device that dumps temperature on a scale on the other DAC I'm willing to weld in some bungs and give it a try.

20psi back pressure will be (0.8 - (20 * 0.0009) ) * 14.7 = 11.4954 AFR instead of 11.76 which isn't too bad, but isn't ideal, I guess.

My manifold looks like this, so would be relatively easy to add bungs to the top or side of each runner:

It would be interesting for me to see in your app if the sensor gets cooked or not. I will put a 0-5v temperature signal on the line that I use for the simulated narrowband output, we will take over skype when i find time to do this.