On 4/12/06, Richard A Jones <jones@colorado.edu> wrote: > > > probably the > > easiest thing to do is to go to an exhaust shop and have them cut you in > a > > whole for an oxygen sensor and weld in a bung then you could use an > oxygen > > sensor to tune. > > You need Ken Lewis's great gizmo: > http://neksiwel.20m.com/photo5.html > The best $22 you can spend.

Another option, for those who prefer a more analog look, is a Lascar EMA-1710 LCD meter: <*http://tinyurl.com/mw7he>* Only drawback is that it has no light, unless you're crafty like Dennis: <http://my.tbaytel.net/guskers/gauges.html> Or you can spend twice as much for one with a built-in backlight (though you'll have to find a way to feed it 5v!): <*http://tinyurl.com/mtkxl>*

These are nice to see what your exhaust looks like in a general sense, but if you want to do any actual fine tuning they're an exercise in frustration. The stock O2 sensor is a narrowband unit, meaning that it only gives useful information right around 14.7 AFR. That's fine for the ECU, which is operating at the millisecond scale with fuel pulse timing and can dance on the razor's edge, but we meatbags end up cursing when a tiny tweak in either direction sends the needle from pegged lean to pegged rich. I ended up buying an Innovate LM-1 wideband sensor unit for tuning (can't have too many toys). If you're not a gadget weirdo like me and can't justify the $350, you can always rent an LM-1 from <Aircooled.net> for $75.

-- John Bange '90 Vanagon - "Geldsauger"