1998 4WD 2.7 3RZ-FE, ~120,000 miles, not driven very frequently, mostly highway miles
During a long road trip last summer, my truck developed a kind of stutter - at cruising speed, the engine would cut out very briefly. It would happen every once in a while, unpredictably.
Not too long after that, it started happening more regularly under acceleration around town.
Having been away from home for a few months, I had the battery disconnected until recently, and needed to get it smogged as soon as I was home and reconnected the battery. On the drive to the smog shop (first time driving in several months), the stuttering under acceleration was *much* more pronounced. At the smog shop, they found the OBD reported that the oxygen sensor and evaporative system sensor both reported "not ready" status (note: oxygen sensor *heater* reported OK), so it couldn't be smogged.
On the way home from the smog shop, the stuttering was almost non-existent.
What I'm wondering:
(1) Seems like the oxygen sensor "not ready" status could be related to the stuttering, but to what extent would it having JUST had the battery reconnected cause the "not ready" status? (and thus be two unrelated issues?)
(2) Not sure what to think about the evaporative system sensor.
What I need to address:
(1) Figure out what is causing the stuttering. I got some mass air flow sensor cleaner and sprayed the heck out of it, so I think I ruled that out. I'm not sure if this is the oxygen sensor(s) or not, but maybe it would be healthy to replace them no matter what (don't think they've ever been replaced, although I hate to make an unnecessary purchase)
(2) Would like to have confidence that it's ready to smog. I have an OBD scanner in the mail...
Advice would be much appreciated.