Delayed EPA's actions.
They are trying to to delay EPA long enough for Congress reach a consensus such that Congress can preempt EPA. The first attempt was the House cap and trade bill.
That’s true, it was a two year delay IIRC. It was also sold as a delay, not a preemption. But a lot can happen in two years: the EPA could do a lot of damage, or the political and weather climate could change enough to make global warming legislation a nonstarter.