when i let off of the gas when i first installed the gauge it would go red (lean). like whenever you shift and stuff. but now whenever i let off of the gas my gauge goes so lean it doesn't register. my vac will go to 25 or so and the gauge won't lite up again until my vac gets back up to about 20...

is this normal? could i have a bad o2 sensor? i thought that the gauge only read in open loop mode, which would mean unless i'm flooring it it doesn't matter what the gauge is outputting. another oddity is that when i first installed it would constantly bounce back and forth from lean to rich if i was just crusing, but now it's pinned on the rich side most of the time, almost like it's reading even though i'm not in open loop operation (maybe i need a new tps sensor). i will be installing a digital o2 gauge soon, but for now i'll have to live with this one.

-bryan
'98 rst

Sounds like a bad o2 sensor, especially after ready your other reply in the MAP sensor thread. The A/F gauge should read 1 led (red) when you let off the gas and most of the time should bounce back and forth. It will read on the rich side at about 80%+ throttle.

It sucks to have to replace everything when you don't need to, but with your A/F gauge acting funny and a lean mixture code, it the o2 sensor would be my best bet.

yeah i know, i'm just trying to narrow it down. i'm almost positive it's not the map or the tps. the fuel pressure is very high because of my wonderfull regulator and my rear bumper is black b/c i'm running so rich, and yet i get a lean code and those wierd a/f o2 conditions. i was going to replace the o2 when i added the new fuel system soon anyways, but again thx for the info, i have to go to work, i'll catch up with you later on IM or something

-bryan
'98 rst