Bettle fault

[StevenB]

I have the following faults on a petrol bug, it will rev on it's own while at idle and difficult to hold revs at a given RPM along with other things, has anyone had this fault before i start replacing bits ? thanks Steve

16556/P0172 - System Too Rich, Bank 1
Possible Symptoms

Irregular behavior

Possible Causes

Fuel system
Excessive fuel pressure
Leaking or contaminated fuel injectors
Leaking fuel pressure regulator
Low fuel pressure or running out of fuel
Vapor recovery system
Air leaks after the MAF
Vacuum leaks
Improper seated engine oil dipstick
Stuck EGR valve
Oil overfill
Cam timing
Cylinder compression
Exhaust leaks before or near HO2Ss.