i hcekced them and they work fine there denso iridiums and ive had them for like 6 months, and i cleaned them just incase. it idles fine it just bogs and backfires like 100000 times when i nial it form idle. and will run like shit. rpms will actually fall and backfires and i caught my yard on fire holding WOT at 3-4 k backfiring and not going anywhere