t2288

Please note that I am a novice mechanic and still learning. I have asked friends that are mechanic and have been "stumped" with my issue. Here is the issue: I have a 1999 Chevy k1500 suburban trying to get smogged. I have received PO327 code for knock sensor. I replaced 3 knock sensors, still receiving same code. I've changed spark plugs and wire, new distributor cap and rotor. Had all oxygen sensors replaced. Vacuum hose are good and connected.

Within the last 6(+) months, my suburban had not started on me on three different occasions. Waited an hour to several hours later to find the suburban started right up. I have noticed that is idles a little rough, seems to be consuming a bit more fuel than usual, and have seen black smoke with I accelerated to pass. When changing the spark plugs, I did notice that a few of them were really dirty and had a lot of soot. Recently the suburban came up with a new code: PO430 for my Cat on bank 2. I can't imaging neither of the code items will stop the truck from starting. I did read that a bad or going bad fuel pressure regulator can be the culprit to my issue?

If any of you out there have any experience with this issue, please if you would send me your responses to figure this issue out. Thank you everyone for your assistance.

Tony