The saboteur class creates magical traps that have the same effect as an actual spellcaster of the saboteur's level casting a spell from the trap's location when triggered. Traps per day and traps known work very similarly to spells per day and spells known for a wizard, and a saboteur can even discover new trap assemblies from a wizard's spellbook.
Strictly by RAW, no.
The saboteur reads
The saboteur uses her level as the caster level to determine any effect based on caster level.
But Improved Caster Level reads (emphasis mine):
Your effective caster level in all spellcasting classes is increased by 4, but no higher than your character level.
As the saboteur does not have the Spells ability, it's not a spellcasting class.
In many ways, saboteur traps behave like spells in trap form
just doesn't quite get you there from a legalistic reading.
Should you be able to use it anyway? Maybe, since it's capped at character level and only affects your trap durations and effects, not number of traps or anything else. I'd allow it, but you'd need to negotiate it with your GM.