2004 Tacoma 2.4 P0171

Hello everyone. After some time chasing vacuum leaks and a plugged fuel filter, I still was getting a P0171-Sytem running lean. I performed a smoke test and nothing that could cause the P0171. Today I noticed a vacuum hose running from the filter box to a solenoid on the driver's side and the outlet ofthat solenoid is a hose going to the intake. This is basically a solenoid to control a vacuum leak. What is this solenoid? It's mounted above the purge solenoid.
Thank you in advance.

 

I’m chasing the p0171 code on a 96 tacoma I just bought. After searching for vacuum leaks and not finding any I’m focusing on the fuel system because I get the hard to start when hot symptom. Have you checked the fuel injectors and pump?

 

I would have thought your 2004 would have the evap system and canister under the bed near the gas tank, but maybe that's only 6 lug trucks.

here is a link to an annotation of the under-the-hood evap components:
VSV for EVAP issues


I assume you are referring to 1 - Purge (to intake) ?

 

Also, lean codes could really be from a number of different sources. Have you tried cleaning the MAF (with MAF safe cleaner)? Checked the exhaust for leaks? particularly the flanges, where an exhaust gasket could be worn out and letting exhaust gas escape?

 

The canister is on top of the tank. There are two solenoids on the driver's side left. One is the purge solenoid and I'm asking about the other one with a light gray connector.

 

You may want to post a picture then, so others can help. I kinda doubt that's the source of the issue though.

Did you check the brake booster? that's a pretty common place to have a vacuum leak.

 

I will post a picture to.orrow when I'm back by the truck. I did check the brake booster and it's good. I have confirmed this solenoid is open, the intake to ingest unmetered air from the airborne. I pinched off the hose and fuel trim percentages started coming down to normal instantly.

 

Here's a picture of the solenoid.