Vacuum leak 2004 ford explorer

Hello ford forums,

I have a 2004 ford explorer and recently the service engine light(SEL) came on. also, my idling is very rough, but drives normal at regular speed. I took it to auto zone to get a code reading. I got P0174 code, which means leans bank 2. I've replaced the intake gaskets, cleaned MAF sensor and replaced an 02 sensor, the problem still exists. Can anyone tell me where the vacuum hoses are located? I believe I have a vacuum leak, I here a hissing noise when I take off.

Look all around the top of your engine. Most of those hoses are vacuum hoses.

Don't let that light hiss sound fool you, it's quite common.

Look for a bad / soft rubber elbow fitting in vacuum line. Common problem with V8.