it’s not gonna be the o2, that’s pretty clear.
on a cold start issue, 2 things you wanna check right off the bat:
- ect sensor. (not the ect sender. not the ect/fan switch. but the sensor). use a DVOM. range it to read Kohm. i’m not sure the exact spec, but it’s gonna read high when cold if it’s functioning correctly. probably in the area of 10Kohms. if it’s reading low when cold, like say under 100ohms, the ecm will think the engine is hot and pull back fuel trim. a cold engine requires an excess amount of fuel to combat HC dropout.
if that all looks dandy, move on.
2. fitv operation.
pull the air cleaner boot off of the throttle body. there should be 2 large ports in the throttle body bore. the lower of the 2 ports will be the fitv port. start the engine cold. feel for suction at the fitv port. if no suction, either the fitv is stuck/bad, or the port is plugged.
try those 2 tests and get back with your findings
