runs rough and jittery at low rpms

I have a 1991 Mazda B2200 SE-5 manual 2.2l fuel injected runs rough and jittery at low rpms check engine light gave obd1 error 44 or 45 (sorry, i forget which one it was) was told it was this part (pictured below) but do not know the name of it, any help?

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