2005 Suburban With Error Codes P0300, P0171, & P0131

[bowtieman427]

Have 2005 Suburban 5.3L 52k miles. Runs fine when first started idles around 900-1k RPM smooth. When it warms up idles a little rough 400-600RPM. When the check engine light first came on it ran very rough at idle and a little rough while driving after the short trip turned off and then started again it ran a little rough at idle and a lot better while driving. It is using more gas. Error codes P0300, P0171, & P0131 checked at Auto Zone. Auto Zone sold me an O2 sensor, but thinking more about it the P0300 code has me thinking there is may be a vacuum leak and the leak caused a lean situation for the O2 Sensor to have its issue. Before I install the O2 sensor. I would like to know:

1) What is the best way to go about checking for a vacuum leak ?

2) anyone have diagrams where to check ? Best way to go about it ?

3) any opinions on what the the problem may be?

 

This is my first post here thanks in advance for any advice

[alwcurlz]

Are you having any difficulty starting the engine initially?

Have 2005 Suburban 5.3L 52k miles. Runs fine when first started idles around 900-1k RPM smooth. When it warms up idles a little rough 400-600RPM. When the check engine light first came on it ran very rough at idle and a little rough while driving after the short trip turned off and then started again it ran a little rough at idle and a lot better while driving. It is using more gas. Error codes P0300, P0171, & P0131 checked at Auto Zone. Auto Zone sold me an O2 sensor, but thinking more about it the P0300 code has me thinking there is may be a vacuum leak and the leak caused a lean situation for the O2 Sensor to have its issue. Before I install the O2 sensor. I would like to know:

1) What is the best way to go about checking for a vacuum leak ?

2) anyone have diagrams where to check ? Best way to go about it ?

3) any opinions on what the the problem may be?

 

This is my first post here thanks in advance for any advice

[bowtieman427]

Are you having any difficulty starting the engine initially?

Starts up normal. No starting problems.

[kchasse]

change the bad sensor and all your troubles will be solved.