P0449 Cadillac

Question

I have code p0449 I replaced the vent valve under the differential the old one and the new one read the same resistances and it is to spec.

I still have the code coming back I checked the wire harness it looks fine.

What else could be the problem.

Before the evap solenoid went out I had an O2 sensor go bad I just left it alone. The O2 sensor is still bad and comes back after about 25 miles of driving or so. I erase it and then the p0449 comes back right a way and then the other bank 2 sensor 2 comes on after a 25 mile drive.

Is it my ECM/PCM or if I replace the bad 02 sensor will it fix both problems

Answer 1

P0449 Evaporative emission control system vent valve / solenoid circuit malfunction

The evap vent solenoid and the 02 sensor share the same 12 volts power circuit. Even if the ECM was damage the 02 sensor would need to be fixed before a new or used ECM is in place or the same situation will ocuur, You can do this fix the problem with the 02 sensor first , and probably sell the vent solenoid on ebay as new

Here the purge and vent it share the same fuse for the 02 sensor

Here the 02 sensor it share the same power circuit for the purge and vent.