Hi, hoping for general feedback, getting e49 code from my 90Cad Deville 4.5, started after head exhaust pipe flange bolt broke (again). I'm fixing it this payday (two weeks), in the mean time, should I be concerned about any further damage from daily driving? Is this big time or a silly nuisance involving emissions?
Car runs excellent very restored, got the code over a month ago, changed the air filter & it went away, just came back this evening. Within the past 2 years :

Rebuilt trans
New cat/ erg solenoid & valve / pcv valve
Resealed motor including Fi orings/ ohms tested good
New water pump fuel pump & filter & tank
New battery/ new starter / new ignition lock cylinder
Oil changed very often / always use 91 /
AC system NOT converted yet, only blows on ECON, (get f48)

.........New rear suspension ( the e49 came up the same day I upgraded the rear suspension) (it is Elc air ride too)....,,..

Any feedback greatly appreciated!Thanks in advance!