Well I seen the AEM wideband o2 with the X wifi for connectivty/tunning but I was wondering if it would even be worth it since I pretty much have a stock s5 motor without an aftermarket ecu. Oh its also $375 so should I spend the 375 on an aftermaret used ecu?

 

Almost every aftermarket ecu has an analog input that can interpret the 0-5v analog output of most wideband manufacturers. If you have a stock s5 motor with a stock ECU dont bother with a wideband and invest in an rtek or an aftermarket ECU (haltech, microtech etc..). most places that do tunes have widebands they will use to watch afr's while tuning

 

The wideband O2 sensor will give you good information, but the lack of tuning capabilities with your stock setup means you won't be able to do much with that information. Once you have some sort of aftermarket ECU and can tune, then the wideband O2 will be helpful. Until then, it's just neat information.

 

where can I get an rtek? and is it only for turbo models? oh my wiring in my car is S4 not S5 motor swap has been done.

 

http://www.pocketlogger.com/?pid=rtek7_techinfo

Here you go man. There's a lot of helpful info on their site and they seem great to do business with.

 

Thanks for the info

 

well, not quite ,, SOME of the widebands have a multiple outputs , one of them is often a narrow band emulation , and the other is ( in some brands ) user definable

if you set up the definable map correctly , you could then use it to feed the stock ECU and thus bias the closed loop cruise leaner ( or richer if porting overlap required so )

not something you would do in preference to a rtek or better ecu
,, but something to keep in mind for those already with a few particular wide band controllers and stock ecus

 

well looking around my garage today and I found a wideband O2 but I have no idea what one it is and it only has the wires leading to a white plug. If I take pictures anyway to identify it?

 

Buying a wideband O2 sensor/gauge was one of the best purchases I ever made for my S4 TII. You said your engine is basically stock now, but as you start messing around with your engine and changing parts, your AFR's will start to change. And knowing if you're running lean or not is a big relief as too lean equals a blown engine. I bought the AEM UEGO for my mildly modded car, but due to a number of different reasons, my car had very unstable AFR's. Honestly, having the gauge and knowing how to interpret the information probably saved my engine multiple times. I've learned a lot about how my engine behaves and runs simply by knowing where the AFR's are in relation to how the car is running.

I have a stock ECU with SAFCII right now, but will be eventually upgrading to a Haltec, but the wideband will always be useful no matter what ECU or engine mods I have. Do you need it? No. Is it helpful? Definitely.

 

I use this one with my rtek in my s5 turbo.
http://www.plxdevices.com/product_in...id=SEMOSMAFRV2
inexpensive, small and plugs right in to be monitored with my palm pilot works great.