just replaced the FPR on my car becuase of rough Idle and poor warm starts. Got all done and the warm start problem was gone!!!! but the rough idle was still there. I had a bad vacume hose, when the car started it would suck the broken hose together and appear to be ok, but on some slitght reving with my head under hood i heard it. L shped vacumne hose was broken (not visible at all, looked perfect) but when i grabbed it, it was 2 pieces instead of one. Replaceing it fixed my idle problem. Now if it would just get nie here (im In Fargo ND where the news is showing hte flooding, luckily in a safe area). good luck.