2-3-2 Error code 855 t5

[merc85]

Hi , i have a fault code 2-3-2 keeps coming up from time to time, BUT only if i'm driving very easy or coasting.

2-3-2 long term fuel mixture too lean or rich at idle

What does the above code indicate? i may add i have a Exhaust blow from my Catalyst could this be the cause?

Car doesnt miss fire runs spot on.

[Justin]

Its probably got an elbow vac hose split and is sucking in un metered air, check all of your vac hoses