When my furnace starts up for the first time, only two of the three burners ignite. The third burner (far left), which has the flame sensor in its path, does not ignite; however, if I blow the flame into its path, the burner will ignite and the furnace will heat without further issue. Sometime, if I let the burners fail the first time, the furnace starts a second cycle and 9 out of 10 times will ignite properly on its own. The furnace is approximately 10 years old, with maybe a month or two's worth of use a year; this problem only began approximately two weeks ago.

I am thinking there is something restricting the flame from jumping over to the end burner. Is there a component I can remove to clean or replace that will fix this issue?