If you do wind up having to replace your o2 sensor, get the oem sensor and not an autozone/carquext/yadayada sensor. The oem ones are the only ones that consistantly last longer than a few months of use.
Matt 1995 Eclipse GS 2.0L, S16g Turbo, 8 Injectors, 26psi
1998 Eclipse GSX 2.3L Stroker, AEM EMS Converted to Speed Density, FP3065 Turbo, 35psi , and so on...