I've been getting a P2196 code lately. O2 sensor stuck rich. I figure the sensor is just going bad as I just keep clearing it with the flasher and it'll come back on a few weeks later. Fortunately, they are much easier to replace on a Duratec than a Zetec. Especially with the FSW turbo kit that makes it right there in front of you on the downpipe.
2007 Focus ZX3 - FSW Stg 2, cams and cossie mani, stock motor, 7.74 @ 93mph (1/8th mile) w/ 1.84 60ft spinning
Built motor on the engine stand!
Shout out to FSWerks and Focus Rising 2012!