Bank 1 running lean

[Towelie]

Okay so this car is pissing me off. At idle, the LTFT's for bank one always stay at around 1.25, where bank 2 usually hangs out around 1.05. If I bring up the revs to around 2500, the LTFTs shoot to 1.00 but the STFTs dip so that bank one is 0.80 and bank 2 at .95. I have swapped spark plugs, coils, and injectors, and oxygen sensors, and not once did the problem follow. Does anybody else have any ideas?

 

[weather man]

Any messing around with the intake? Vacuum leak on that side?

 

[Towelie]

I took it off to install cmcv deletes. I'm gonna get some carb cleaner and spray around the gasket areas tonight when I get home listening for leaks

 

[BruceH]

Okay so this car is pissing me off. At idle, the LTFT's for bank one always stay at around 1.25, where bank 2 usually hangs out around 1.05. If I bring up the revs to around 2500, the LTFTs shoot to 1.00 but the STFTs dip so that bank one is 0.80 and bank 2 at .95. I have swapped spark plugs, coils, and injectors, and oxygen sensors, and not once did the problem follow. Does anybody else have any ideas?

Everything was fine prior? You may know this already but I'm going to repeat it anyway.

Short term trims are an immediate correction via the o2 sensors to a lean or rich condition. Long term trims are predicted based on previous short term trims. These corrections are only in closed loop and they correct what the maf xfer function is commanding for fuel.

If you installed deletes but didn't tune for them it could be part of what's going on.

 

[obsrt86]

For the longest time I had a Bank 1 lean code and for the life of me couldnt find it. With the help of my tuner, we pinpointed what could be the problem and the result was a bad header gasket. Maybe something to check out, especially if you have aftermarket headers.

 

[Towelie]

So I spoke with lito, and he's thinking it's an exhaust leak. I took off the pipe that goes from my passenger side exhaust manfold and it looked like it wasn't sealing correctly. I dabbed that up with some ultra copper RTV. I'm letting it cure now, hopefully that seals her up.

 

[dre256]

Now I have the 5.0 but I was getting lean on bank 1 or 2, I forget but was when I hit about 5k miles on it. After 3 times at the dealership last time had car for 2 days with ford tech helping figure it out, came out to be a combination of an 02 sensor and the crank position sensor seal was bad.

 

[Towelie]

I got it fixed. Turned out the passenger side collector was leaking. Sealed it up and it's working fine now