Im getting camshaft codes and misfire codes I already replaced one sensor how can I find out what else is causing the misfire

It was working when I parked it in the garage. One week later when I started it the guage went to full, then went to empty. I filled the tank that day and it remained on empty.

My 2003 Seville STS, VIN 9, needs new transmission. Can I replace it with one from 2003 SLS or DeVille? Will one from cars model year 200-2002 work? If not, can I swap transmission AND computer wit SLS model? I don't care about loosing some performance, I just need to repair it for less.

I replaced the fuel pump when it failed. Car drove fine after that, however, the gas gauge still didn't read correctly. The car quit again about a month later with no warning. In fact I started the car after I came out of a store, turned the car back off after a minute to go into another store. When I came out again about 20 minutes later it wouldn't start. Once I got the car home we played around with it a little and after taking the fuel pump out and then putting it back in because we noticed a disconnected wire the car started. We let it run for 5 minutes but then it wouldn't start again a few minutes later. Any ideas before I purchase another fuel pump? I've had a friend do this work for me, not a garage.

Car is hard to start, but when started it ran fine. Now it stalls, won't tack up even at full throttle. Acts like it's running out of gas. Then will spit and sputter, then straiten up and run fine again? HELP!

diagram available showing these locations,

my buddys 2003 seville sts has a pwower steering whine, we changed the pump rack and lines, but the whine is still there. reason we changed them is that the car sat for a couple years and he wants all new parts. i have been a tech for 15 year and this is the first time i have come across this, i thought maybe bad rack or pump so changed them again. i just cant see getting two bad racks or pumps. is there something i am missing here. please help

i am not getting a warning or code, it olmost sounds like a air bag.

Check engine light stays on.

It does not show as a diagnostic code on my instrument