Car shutting off
I have a 2005 Mitsubishi Lancer es I just changed
the mass air flow sensor and I believe the
downstream O2 sensor (the one underneath the
car) now my car runs a little smoother but the check
engine light came back on and my car when idling
or at lights or even reversing it shuts off or I have to
press the gas to keep it from shutting off what is the
issue now because all of a sudden the new code
reads emmisins issue catalytic converter but that
didn’t come up the first time and it didn’t start with
the shutting off and new emmisions code until I
changed those two sensors ? What can be the
issue