Just finished fabbing up new downpipe, bolted it all together, and went for a spin, but...

My wideband sensor just outputs that i'm stoich. Under deep vacuum, the link ecu shuts off fuel, but the wideband just keeps outputting stoich. With my old downpipe, the fuel is tuned pretty close to that green A/F target line.

The only difference from my old downpipe is that I made the tip only protude into the flow by a few mm by sticking a spacer before the O2 bung. (I heard it gave an extra .25 hp worth of exhaust flow )

You guys think it's because of the low tip protrusion or my sensor dead?

 

It needs to be fully in the exhaust to work properly. I would definitely suggest you stick it all the way in.

 

This just happened to me last week on my AEM. Guage just sat at 14.8. Double check the connections of the two plugs in the back of the gauge. Mine were both in, but pushing in on both of them made mine work again and has been fine for the last few days. Might not be your problem but an easy check.

 

I got the controller type wideband, so there isn't gague, but i'll double check all the connections tonight. *cross-fingers*

 

One of the engine builder that I know said that the wideband sensor had some sort of pump that sucks exhaust in. That's why I went ahead and did that.

Does it really suck gases in?

 

If the bung is sitting on the pipe, youre fine with exposure to exhaust. Check all your connections.

 

It has an oxygen pump to pump exhaust into a second chamber, but it should still be in the stream. Even though wide bands have heaters in them, they still need direct exhaust to heat up properly. Normally o2 spacers are used if a newer car is throwing oxygen sensor ecu fault codes. By spacing it farther away, the sensors simply don't work nearly as well.

 

unplugged everything, and repluged it all back in..

and it works!!

Hopefully, It'll last me through my coarse re-tuning, until I can make it to the dyno.