[Boxstard]

Went through the same issue a year ago shortly after I bought my car at 69K miles.

First tried to clean MAF a few times but did not do it, then I bought new one as it was cheaper than O2 sensors, still CEL kept coming back... so moved onto O2 sensors and under close inspection they were cheap no-brand with wires splined/ soldered in nasty way... so I bit the bullet and bought four O2 sensors, genuine Bosch with correct pigtail connecor, found the great deal with rock auto at $72 each, still not cheap when buying four but they did the trick!

I read that O2 sensor wires are supposedly designed to pass tiny air lengthwise under insulator jacket, so splining or soldering may affect sensitivity, true or not.... it made sense in my case.

PS. This past winter I battled another dreaded CEL issue due to bad check valve and switch valve in SAI system. Pain to get access to replace them but has been CEL free for the last 5 months, car running like a champ!!!