2010 ford fiesta zetec ws

[russellw]

There are a number of ways around the check engine light that don't require tuning although the addition of the extractors and HFC would probably benefit from a decent tune.

You can reinstall 02 sensors, use dummy sensors, replace the sensor(s) with Spark Plug Non-Fouler(s). There is a post here that I wrote describing how to do so.

Cheers
Russ