Codes P0171, P0174, P0430, P0300

Hi and thanks for using 2CarPros.com.

As far as a vacuum leak is concerned, yes to all of your questions. They can cause a lean mixture as well as a random misfire. What I need you to do is use a vacuum gauge to check for leaks. Here is a link that shows how it is done. Also, behind the throttle body, there is a vacuum hose connected near the bottom. If you follow it, you will find a 90 degree elbow. These elbows are known to dry-rot and leak. So, make sure to look for that.

Here is the link:

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

Check these things and let me know what you find. Also, if you have other questions, let me know.

Take care,
Joe

All you need to do is fine a vacuum port on the intake or a vacuum line. Any intake vacuum port will work.

As far as the PCV, that should be a much bigger hose. You will be looking for a smaller one. However, the PCV can leak just as well.

Good afternoon.

The 430 is for catalytic converter bank 2. That is the drivers side

171,174 is for long term trim reading high which is lean.

Check

Fuel pressure. Would also cause the 300 code.

Mass air flow sensor. Make sure the connector is clean and tight. Check the hose that goes to the throttle body and see if it is ripped open anywhere.

PCV make sure the valve is not stuck open.

Intake manifold. Common for the intake manifold to warp and leak vacuum. You can verify by a smoke test to see if it is leaking.

Roy

If you gutted it then that is why the code is set. There is no cleaning of the gases. It needs to be replaced to turn out the light.

You can rent a fuel pressure tester. You get it at a parts store. There should be a schraeder valve on the fuel rail.

There is no such thing as cleaning a mass air flow sensor. The carbon is burned on the sensor and there is no cleaner that can get it off.

Roy

Fuel pressure needs tested at the schrader. The only other way is to disconnect the fuel supply and place a T in it. Then you would still need a pressure gauge to check it.

Hi again.

The 1131 indicates a lean mixture and the computer has maxed it ability to compensate. See pics 1 and 2 for possible causes. The 1151 is the same thing for the opposite bank.

Take a look through the two pics I attached. See if anything clicks with a possible issue.

Also, these engine often times have exhaust manifold leaks. It will sound like a ticking oftentimes. Is that happening?

Let me know.

Joe

If the exhaust manifold is leaking, it would be most obvious when starting it and when the engine is cold. The easiest place to hear it from would be the front wheel openings.