Throttle body - clean it

Just got the car back from the garage after an Air/Oil separator repair and the idle is "breathing" between 800 and 500 rpm.
The car drives fine, but it doesn't seem quite normal.

Would be interested in the Board's thoughts.

Possibly affecting the MAF? Other lines that affect vacuum? Just a conjecture. Others will have authoritative answers.

Minus 40 degrees... Is that Fahrenheit or Celsius?

Classic dirty throttle body. Do it yourself, no parts to replace, cost is zero .. or maybe a can of spray cleaner and a rag.

Peace
Bruce in Philly

Some are thinking O2 sensors, but I think the problem may be with the Purge line...comments/thoughts?

Could be purge line/valve related. The P0446 error code points to that. The P1128/P1130 are lean codes which suggests unmetered air is getting into the engine intake. A line could have been disturbed during the AOS R&R. As these cars age the various rubber hoses become more fragile and it doesn't take much to possibly cause one to crack. Most common place is there the hose connects to a fitting and at the bottom, but of course you need to check the entire line, or lines.

Idle problem solved after cleaning MAF sensor and throttle body.


CEL codes (P0446, P1128/P1130) and constant shutoff when fueling/trouble restarting when the engine is hot:
- resolved after changing out the regeneration/purge valve (part number: 996-110-12906 $221)... it is the one under the intake manifold.

500 miles Boston/NY roundtrip...no new codes.
Hope other will find this helpful in the future.