"second important factor" is a correct and usable phrase in written English.
You can use it to refer to the second most important factor that is influencing a situation. For example, "Time management is an important factor in academic success, but the second important factor is having a solid support system."
A second important factor is the environmental matrix.
A second important factor is the specific formula used to translate votes into seats.
A slight change in trend is shown by the flexural modulus, where the second important factor is float length and the third factor is pressure time.
The second important factor in the matter of yellow-cab economics is the question of which form of transport will have an easier time attracting cars' necessary element: drivers.
The main base outside Seoul a source of friction with the locals, as are the cluster of marine bases on the claustrophobic Japanese island of Okinawa will move too.The second important factor is technology.
Further, air entrainment as a second important factor governing mixture preparation is discussed in combination with air-distributed and fuel-distributed mixture preparation, combustion chamber design, in-cylinder flow (swirl, turbulence, etc).
A third important factor in today's show dancing is the revivals.
In 2009 it was 2.4.A third important factor is obesity or, rather, the physiological complications obesity brings, such as high blood pressure and type-2 diabetes.
A third important factor affecting Tibetan herders, whether recognized by them or not, is climate change.
A fourth important factor is the site of injection, especially concerning large volumes.
First important factor, in this case, is the Variety of experience of that candidate in different areas such as article talk, Wikipedia talk, admin notice board, and other RfA's.
