1996 328i obd code questions

[bmw envy]

Hello all, new to the forum...love it looks great!! Pulled some obd codes from the 328i...420, 1421 1423.. I checked the sec air pump itself..runs at startup...no noise etc...does it sound like the metal check valve is bad? Also the code 420? I heard this may mean bad cats? Any ideas? 144k on the clock..Thanks!

[Tefal]

check the vacuum pipes around the inlet manifold area

[jehuflores]

Hello all, new to the forum...love it looks great!! Pulled some obd codes from the 328i...420, 1421 1423.. I checked the sec air pump itself..runs at startup...no noise etc...does it sound like the metal check valve is bad? Also the code 420? I heard this may mean bad cats? Any ideas? 144k on the clock..Thanks!
I'm kinda new here, the only code I do know is 420, and it's not for vehicles.

sorry I can't be of help, just thought it was funny... :D