Engine code P0300 and stalling?

OLIVERERIC423

MEMBER
2001 CHEVROLET SILVERADO
V8
AUTOMATIC
550,000 MILES

This truck was given to me as a gift. It had been sitting for 4 years. We put gas in it, and it started right up. However, any time we put the vehicle in reverse or drive, the engine stalls immediately. It has the code p0300 and that's the only code currently being pulled up. The catalytic converter has been cut and straight piped from my understanding and it has a lot of miles on it. I'm just trying to figure out where the best place to start to look for the problem is. The spark plugs were changed not long before it got parked. It has a brand-new battery on it.

3 Replies

JACOBANDNICKOLAS

MECHANIC
108,289 POSTS

Hi,

When you place it in gear, does the vehicle lurch forward before stalling? Also, have you checked for diagnostic trouble codes? When it is running, are you able to feather the throttle to keep it running and place it in gear?

Please keep in mind, this could be several different things. If the check engine light stays on when it is running, scan the computer.

Here is a link explaining how to scan all modules:

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

If the light doesn't stay on and the vehicle doesn't lurch forward when placed in gear, I would suggest checking for things like engine vacuum leaks and checking fuel pressure.

Here are two links explaining how this is done:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Let me know what you find or if you have other questions.

Take care,

Joe

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Saturday, June 24th, 2023 AT 10:51 PM

OLIVERERIC423

MEMBER
15 POSTS

The only code I've gotten on it has been p0300. I know it is a multiple misfire code but don't know if it's the plugs causing the misfire or what. The truck doesn't lurch when put in gear, just cuts off. However, when continuing to press on the gas lightly, it does continue to run when put in gear. I'm not sure what would cause it to cut off when put in gear but only when not continuing to press on gas along with the braking. Thanks for your help!

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Monday, June 26th, 2023 AT 2:47 PM

JACOBANDNICKOLAS

MECHANIC
108,289 POSTS

Hi,

Since it is a random misfire, chances are it is either an engine vacuum leak or a fuel pressure issue. Are you able to perform the tests in the links I attached above?

I have to ask. Is the mileage you indicated, correct? Is this the original engine? If it is, we could simply have low compression from wear.

Let me know.

Joe

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Monday, June 26th, 2023 AT 10:09 PM