The CEL that won't die

[Perfectlap]

CEL 1276 (fuel metering control) and 0153 (bank 2 sensor 1 ckt slow response).

First came up before I replaced the upstream O2 a long time ago. Codes came back.

Replaced the MAF, codes came back. My mechanic checks with Autologic thing, zilch.

Replaced the headers after finding hairline cracks at joints. Went ahead and replaced all four 02's at 100K miles. (cough EXPENSIVE)... Codes came back.

I clear the codes with the scanner, hit a dip in the road on the highway, CEL comes on.
Frayed wiring? This has been going forever...