to cut a long story short, my car is running decat for 2 months, now it wont idle correct, high low revs all the time, cleaned idle controle valve, maf sensor, wd40 all connections

just about to put new cat on cos its going on diagnostics 2moro, is it worth giving the lamda sensor a clean / soak in petrol while it is out?

(its a 1.8 zetec escort cab)