p0101, p2178, p2188, p0133 codes 09 Volvo S60

[wrecks]

139k miles. car hunts at idle. engine light came on received p0101, replaced MAF cleared faults
engine still hunts at idle. code p0133 replaced O2 sensor cleared faults.
engine light came back on p0101, p2178, p2188, p0133 codes
after a lot of reading on different sites, I cleaned ETC it was really gummed up.
cleared faults, engine runs smooth as silk