Would that regulator also cause the 550-600 RPM idle while sitting at a red light? Dumb question for everyone...the vacuum line that everyone is talking about....is it supposed to be easily slipped off? Is it supposed to be "locked" in somehow?

As for getting it checked professionally, even though I work for a dealership in the service department, getting those techs to do anything is impossible. I will talk to a tech on Thursday when I go back to work and ask him to thoroughly check th FPR.

Other than this issue, I absolutely love driving the car.

Since spark plug wires are on the top of the list as far as probable causes for this horrible code, I am getting new ones. Whether they are the cause or not, knowing they are changed will give me piece of mind. I am getting Taylor 8mm Street Thunder wires. The plugs are all brand new, so these should help.

It's highly recommended to stay stock with the ignition system, ACDelco plugs and wires (just avoid BOSCH at all costs on the plugs)

I am going to bring the car in to work Thursday and try to get one of the techs to chase down this code. I don't want to just throw parts at it hoping it will fix it.

I am going to pick up a Fuel Pressure Regulator. I took the vacuum line off and I smelled gas. None came out, but I smelled it. That should work. I cancelled the spark plug wire order.

Update: The new fuel pressure regulator is in. The idle still wants to go to 550 RPM. Lately it has been steady at 600 RPM. I am beginning to think there is a vacuum leak when at idle. I will get it checked soon. There is no hesitation when I hit the gas. Just that the idle is real low at stop lights and it is on the verge of stalling.

My code was traced to a weak fuel pump. Not happy about it. Now I am trying to figure out how to pay for it and the level sensor.

Any good places to order them from?

my fuel pump is a used unit from a junkyard never had a problem with it as far as stalling and it was 50 bucks lmao but remember this was when it did not run and we just wanted to see if we could get it to run. turns out it was a pretty solid pump.

Plugs= check
Wires= check
Fuel pressure regulator= changed
Fuel pump ( as recommended by Chevy) = replaced

P0300 code is still there. It is acting up worse with the new fuel pump. What other options do I have? I think I have low voltage to the pump causing it to be weak.

Looks like I was wrong. The new fuel pump was the answer. At red lights, my RPMs stay at 700. The car likes to act up a little when stopped on a hill for a red light, but other than that, everything is great. I owe thr Chevy dealership's service manager an apology tomorrow.

This was my first encounter with the P0300 code. I hope it is my last. Onto the bext phase of this project. ... the body.