Why the time difference between the executions?

The attached plan has two executions of the same proc. The only difference is the parameter named @onboarddeviceid. For the first one, that doesn't return any rows. The second will return one row.

the first execution is 4+ seconds while the second is subsecond. I can't find a reason in the plan for the difference.

For the value 141 which has one row returned, here is the relevant histogram.

 RANGE_HI_KEY    RANGE_ROWS    EQ_ROWS     DISTINCT_RANGE_ROWS    AVG_RANGE_ROWS
 140                    0            388147.2 0                    1
 143                    145278.9    222512.7 1                    143788.9

Here is the same for the second value that doesn't have rows. Best i can tell these histograms show the same information which is really nothing about the value returned.

 RANGE_HI_KEY    RANGE_ROWS    EQ_ROWS     DISTINCT_RANGE_ROWS    AVG_RANGE_ROWS
 192                 0            343769.7 0                    1
 195                    16177.69    295173.2 1                    16011.77

I have also forced a recompile (sp_recompile) on the proc and ran them in the reverse order. that doesn't help either.

(me and this editor rarely get along. the format is all goofed up)