Lean codes for bank 1&2
Thread Starter
Junior Member
Joined: Nov 2024
Posts: 8
Likes: 2
From: Texas
Lean codes for bank 1&2
P0174
I’ve changed the pcv valve and hose egr fuel filter mas air flow sensor air filter fuel injectors and the 4 o2 sensors
took it in to have the vacuum lines tested for a leak mechanic said that wasn’t it
when I got it back the light was off 30miles down the road it came back on still sluggish on acceleration and it died on me yesterday started right back up
the only other thing I can think of is the fuel pump
anyone got any advice am I missing something or is the pump the last thing on the list?
I’ve changed the pcv valve and hose egr fuel filter mas air flow sensor air filter fuel injectors and the 4 o2 sensors
took it in to have the vacuum lines tested for a leak mechanic said that wasn’t it
when I got it back the light was off 30miles down the road it came back on still sluggish on acceleration and it died on me yesterday started right back up
the only other thing I can think of is the fuel pump
anyone got any advice am I missing something or is the pump the last thing on the list?
2004 F150 5.4 Lariat
Joined: Dec 2012
Posts: 956
Likes: 156
From: Summerville, SC
P0174: System Too Lean, Bank 2
Since the issue isn’t also showing as P0171 (Bank 1), it’s seems unlikely that the problem lies in the fuel or air delivery systems for both banks, such as the fuel pump or MAF sensor.
Instead, I’d focus on diagnosing issues that specifically affect air or fuel delivery for Bank 2. Checking the air delivery is probably the quickest approach. You can spray water around the intake manifold for Bank 2 while the engine is idling and listen for any changes in engine speed. This could indicate a crack or a leaking gasket.
For the fuel delivery on Bank 2, you’ll need to inspect the fuel injectors. I recommend removing the Bank 2 injectors, positioning them over some cardboard, and having someone crank the engine while you observe the spray pattern. If one injector sprays less than the others, it may be clogged, faulty, or receiving incorrect voltage.
Since the issue isn’t also showing as P0171 (Bank 1), it’s seems unlikely that the problem lies in the fuel or air delivery systems for both banks, such as the fuel pump or MAF sensor.
Instead, I’d focus on diagnosing issues that specifically affect air or fuel delivery for Bank 2. Checking the air delivery is probably the quickest approach. You can spray water around the intake manifold for Bank 2 while the engine is idling and listen for any changes in engine speed. This could indicate a crack or a leaking gasket.
For the fuel delivery on Bank 2, you’ll need to inspect the fuel injectors. I recommend removing the Bank 2 injectors, positioning them over some cardboard, and having someone crank the engine while you observe the spray pattern. If one injector sprays less than the others, it may be clogged, faulty, or receiving incorrect voltage.
