G20 - hesitates while driving after changing plugs and wires..wont go over 80mph

[lady_tech]

I changed my spark plugs and wires on my 2000 infiniti g20t...i always change wires 1 at a time to keep firing order. i first bought some autolite pre-gapped plugs.put them in and car hesitated and so to start off driving so I went and got some autolite plts that i needed to gap at .44..made sure wires all down..same issue! car has to warm up first before i can take off..then hesitates and jumps (its a 5 spd) acts like its running out of gas or something. when it does that if i press the gas down is slows up so if i ease off and barely press gas it will go...NOW it making some rattling machine sound from back right side of engine behind where power steering fluids is..and today that sounds is joined with a "hissing" sound!!

To note the maintenance i personally did so far: replaced cat converter, replaced starter, replaced bank 1 sensor 1 O2... check engine lite is on says its bank 1 sensor 2..HELP!!!

[RED_DET]

Normally a hissing sound is the sound of a vacuum leak somewhere, which would explain the car's behavior. The rattling sound you speak of could be anything, rod knock is the only thing that comes to mind right now. To be real honest, I would have never put auto-lite plugs in my car, especially the SR20. It is very picky and I have always used NGK plugs and not platinum tipped either. Either NGK BKR6E for NA and BKR7E for Turbo application. You did gap the plugs correctly @ .44 for NA motors. If you didn't have these issues with the old plugs, then we can safely say remove those junk auto-lites and at least put the old plugs back in for now until you get the ones I recommended.