Ok, here are the error codes I read using DIS.
"2C2E Oxygen sensor before catalytic converter 2, overrun check -Signal during inertia fuel shutoff below" (can not see after that - is it Threshold?)
"2C3E Oxygen sensor before catalytic converter 2, line fault - open circuit, pump current path or virtual gro" (I can not see any further).
2EF5 - Map thermostat activation - open circuit - Fault currently not present.
The thermostat heater element error code (P0597 OBD code with scangauge) used to show until 2 days ago. It has been there forever. But now suddenly it says fault currently not present. It was there a day after starter replacement along with p0000 which might have come because battery is disconnected. Now both of these are not there.
I am somewhat puzzled here.
Is it possible that because of disconnected O2 sensor I am getting rough idle during start-up(warm or cold start), not a vacuum leak?
Also does this connected needs to be removed for removing intake manifold?
Anyone can they post/link photos of the location of this O2 sensor and wiring routing of this sensor?
Also, how come "Thermostat heater element open circuit" cleared itself?
FYI: I got a replacement thermostat and planning to replace thermostat and flush coolant. But now, if this is not an issue, I will work on it later.
Also, registered new walmart OE replacement battery which I replaced before starter replacement.
http://www.walmart.com/ip/EverStart-...ttery/16782659