why is my grand vitara missing an rough idle worse on a cold start on 1999 Suzuki Grand Vitara

Ive changed spark plugs and wires o2 sensors map sensor ecm t.p.s sensor and still rough idle and missing timing is good and no intake leaks what will fix this car!!

Asked by for the 1999 Suzuki Grand Vitara
Have it scanned for codes and post here so we can advise..
there are no present codes or historical codes on the presnt ecm or the one that was replaced