constant limp home

[drjurman]

I have a 2002 s60 Non turbo. Its been running lousy for a while but no CEL. Low idle, hunting, to low idle stalling, and now constant limp home mode.
Using the cheapo OBD scanner three codes come up. P0032, P0507, P2177. I'll check with the better scanner in the morning.
I've replaced the MAF this evening, Should I go on to the Upstream O2 sensor or look into something else. I've gone to a couple of forums and ETM keeps showing up. Is there a positive way to prove or disprove a bad ETM? car has 140k.. I just spent a mess of money on front end and sunroof repairs, Love the car, but running out of money.