Newbie questions.

[12sec.5.3]

Hello all. I'm new to the tuning and have some begginner questions. I need help making changes to my fuel curve. Without a wideband I guees I have to read H02 voltages. What numbers should I be looking for. Right now I'm seeing .898-.910 and .920 on the other side. What tables do I make changes to?? Thanks in advance.

[nco663]

I think you need a wideband so you use a 0-5v signal. The stock sensors are like rich and not rich (narrowband) 0-1v signal

[12sec.5.3]

So are you saying that I won't get my tune close if I don't have a wide band?

[Black02SS]

So are you saying that I won't get my tune close if I don't have a wide band?

It COULD be close, but you will never know without having one. You can pick up a LC1 for under 199$ if you look around. That is pretty inexpensive to ensure the car is tuned properly and has the correct AFR.

[dfe1]

You can tune idle and part throttle with a narrow band because it's pretty accurate when air/fuel ratio is stoichiometric (14.63:1). The further the mixture moves away from 14.63:1 in either direction-- rich or lean-- the less you can depend on narrow band readings. I once changed air/fuel a full ratio (as measured by a wide band) during a dyno test session, and narrow band voltage only changed by about 40 millivolts. The reason for this is that although narrow band output voltage varies as air/fuel ratio changes, it's far from linear. High 800 to low 900 millivolt readings used to be the target for WOT operation, (before the days of affordable wide band sensors) but most tuners found out this was not dependable. A narrow band O2 sensor actually serves as a switching device because the only thing the system cares about is whether the reading is above or below reference voltage (usually about 450 millivolts). Anything above reference voltage indicates a rich condition anything below it indicates lean (with respect to 14.63:1).