I've had this issue a little while - like many people I guess, time is short and being able to leave the car at the garage and being car-less is something I've been putting off, as the only issue was when it is cold and needing to warm it up for a few mins.
Anyway:
2001

Alfa 147 1.6ts 105
Issues:
low power if I try and accelerate whilst cold it misfires / coughs / exhaust pops, after 1-2 mins- no misfires - runs fine, may be a little low on power but I was in a v8 before this so hard to tell lol.
Last few days:
Difficulty cold starting - can't accelerate at all when cold - backfires - car feels like you are engine braking, when trying to accelerate.
But seems to run fine when warm.
Errors:
p1178 - mixture 2 strength(multiplicative) Signal High - Fatal - Light On - Present Now
p1177 - Mixture correction(multiplicative) Signal High - Fatal - Light On - Present Now
p0150 - Lambda 2 signal above CATAL - No signal - Stored - Light On - NOT Present Now
p0100 - Air Flow Meter - Signal Low - STored - Light On - Not present Now
p0300 - Misfires detected - Signal High - Stored - Not Present Now
p0303 Cylinder 3 - Ignition Failures - Stored - Not Present Now
p0302 Cylinder 2 - Ignition Failures - Stored - Not Present Now.
I got my cable thru the post today, cleared the errors to see what would come back, drove it around 3 miles - no errors have come back on, however it was warm when I drove it and it drove fine warm before - now it's very poor. It's hard to rev above 2 and get any speed in it at all. I'll take it for a longer drive later - let the ECU try and figure out what's going on again - I didn't really want to be in the way of everyone, roads were quite busy and it was difficult to get above 20 or 30mph.
I was thinking MAF before the cables came, but wanted to get it hooked up to confirm.
The whole Lambda signal thing has thrown me, but TBH I know NOTHING about cars, all my thinking on MAF was due to reading a heap of posts on here on similar issues.
Thanks in advance for any advice given!
Edit for extra info - car idles a tiny bit under 1k rpm - steady as a rock warm or cold.
Edit for even more extra info lol - Average Mpg - 33.2 - (with average speed of 24mph) fuel use seems fine.