Solved P0174 code.

[seanddrisc]

I have an 02 4.0 that runs rough and throwing po174 code replaced one rotted out vacuum line replaced plugs car has 126,000 mi anybody have any Ideas I keep getting told replace intake gaskets but I don't think that is problem causing it to thow a lean code, I am wanting to sell vehicle and trying not to just throw parts at it just to get it fixed I had to dealer and light was off AT TIME BUT STILL KEPT CODE so they told me they didn't know what to do?

 

[BrooklynBay]

Spray intake cleaner around the outside of the intake manifold to test the gaskets. The idle should change if the gaskets are leaking since the cleaner is drawn into the intake.

 

[fritz24]

You need to be sure if your issue is only in bank2. Pull the PID's LTFT on bank1 and 2. Tell us the value. Be sure to do this while engine is running, if the value is normal at idle and get worse when rpm change it is injector issue. But if the value is too high and goes to normal when rpm changed then it is a vacuum leak. Sometimes you could only have a p0174( above 25) while the other bank is also high(+20) which is below threshold and doesn't trigger MIL.

 

[seanddrisc]

po174

stft b1 3.9 ltft b1 3.1stft b2 29.7 ltft b2 24.7engine rpm 1065 here are the values I hope this helps Thanks for input

 

[fritz24]

What are the values at idle? We need to compare it in values with rpm changed. Nway it could be a clogged injector on bank 2 and try to torque the bolts on intake manifold. Or a leak in the exhuast manifold on bank 2. None of which checks out, O2S1 bank2 could be sending a wrong signal. Your scanner can read volt on O2 sensors? I'll send you the reference values when i reach home.

 

[seanddrisc]

po174 Update fixed!!!!

just an update my oxygen sensor was bad so I went and replaced both the one on the drivers side was the hardest one to get out it was rusted and stuck in the hole I had to remove driveshaft in order to get out ,I napprecate everyones help and really appreciate this site!!!!!

 

[BrooklynBay]

Thanks for the update! Your thread is now marked solved in green letters.