AFR Ratios

**Mawhitey** · 11-03-2008 02:56 PM

Ok i have a glow shift AFR guage fitted, it splices into the narrow band Lambda sensor. At WOT it drops below 10:1 and on coast in gear its 17:1.

Under normal driving it flickes between 10 and approx 13.5, then as soon as i go WOT it drops to the floor. I know that the guage isnt calibrated but surely it cannot be that far out. I bought it as a way of keeping an eye on the AFR to keep the EGTs acceptable, i realise that the low AFR will the EGT down, but at the expense of fuel economy and performance.

The only change since being mapped is the exhaust manifold and FMIC neither of which should have an impact i can think of. So anyone have any ideas?

Is it down to tuning or do i have a faulty componant somewhere?

**mike-2ptzero** · 11-03-2008 03:27 PM

narrrow band AFR gauges are worthless and are not designed to work with a turbo car, they were meant for NA cars. Basically you just have a disco ball in your car now.

**Mawhitey** · 11-03-2008 03:29 PM

AHHHHHHHH!!!!! That i didnt know !!! so i would need a wide band with an additional o2 sensor bung welded in?

So what shall i log to make sure the afr is good on VAG mike?