P0174 Bank 2 P0174 Error Code

[Cheetokps]

Hello, the last few months I have occasionally been getting a P0174 code, stating bank 2 is running too lean. I replaced all 4 O2 sensors but it did not help.

Thanks to @AndyG i learned a bit about fuel trim from this site and tested it with my code reader. At idle, the short term trims hover around 12%. When I go up to 3k rpm they’ll settle around 30%. Based on that link its not a vacuum leak, and could be the MAF, fuel pressure, or injectors.

Anyone have any experience with this, or know any other relatively easy tests I could perform at home? I did clean our my throttle body well last year which I saw mentioned on another post, maybe I could try that again more thoroughly. Preferably would like to do this myself instead of a shop, but some of the tests I saw look like they’d be more suited for a shop to do

 

[Jerry Bransford]

I had a bad pre-catalytic converter that was causing the PCM to send out bad O2 sender codes. That particular pre-cat eventually totally failed and spewed its innards out to flow downstream into the main catalytic converter and nearly completely plug it up. When that happened my speed went from 70 mph to 5 mph max on the highway coming home from a wheeling trip. Replacing all of the cats fixed everything including the erroneous O2 sensor codes and misfires.

 

[CharlesHS]

Have you checked for exhaust leaks (cracks in the exhaust manifold) where the exhaust tubes intersect ?

 

[Cheetokps]

Have you checked for exhaust leaks (cracks in the exhaust manifold) where the exhaust tubes intersect ?

Only briefly once, I can check again. It would be visible? Or check with soapy water or something? I know theres a way tj do a smoke test but probably wouldnt be something i could do at home

 

[CharlesHS]

Examine the exhaust manifold while its cold and look for carbon tracks around where the tubes intersect.

 

[CharlesHS]

Only briefly once, I can check again. It would be visible? Or check with soapy water or something? I know theres a way tj do a smoke test but probably wouldnt be something i could do at home

Examine the exhaust manifold while its cold and look for carbon tracks around where the tubes intersect.

 

[Cheetokps]

Examine the exhaust manifold while its cold and look for carbon tracks around where the tubes intersect.

Cool thanks, I’ll try that when my engine cools down