Nikuk
8
Are you using the stock O2 sensor?
or
Are you using an aftermarket wideband?
The cheapest Wideband (0-5v) gauge will be ~$100 new… for just a gauge.
The cheapest Narrow band (0-1v) gauge will be ~30 new.
NB gauge won’t be a waste persay… it simply won’t accomplish anything by having one.
WB is a worthy investment while you’re tuning the car.