Can’t shake these codes P0174 & P0171

[EasternYeti]

Looking for some collective input here in regards to my vortec. Having some work done and the codes P0174 & P0171 are turning out to be pretty much impossible to resolve

MAF: less than 9 months old (it’s clean)
02 sensors: relatively new, about a year
Fuel pressure: good pump is new(er)

What are some of the real odd ball things that would potentially cause banks 1&2 to run lean? Given this information and what’s already been done I’m at a loss for what else’s it could be.

Thanks in advance

- J

 

[MANUCHAO]

I went through this over the summer....Same codes P0171/P0174 and P0101
Really did not affect driving, but it was annoying to see that light come up....

What I replaced was, MAF sensor, Fuel Filter (wix 3737), and Fuel Throttle body (DBW)...
The FTB was original to the engine.... personally I think this was the cause of the lean readings, but I am no mechanic.....
Also cleaned the Toyota Air filter, double checked the intake pipes for any leaks after the MAF.

I did notice the post-cat 02 sensor wire making a slight contact with the drivers side CAT, but after further inspection the wires were not compromised....

Codes were deleted manually and after about 100 miles all seems fine.....

Good luck...

 

[EasternYeti]

I went through this over the summer....Same codes P0171/P0174 and P0101
Really did not affect driving, but it was annoying to see that light come up....

What I replaced was, MAF sensor, Fuel Filter (wix 3737), and Fuel Throttle body (DBW)...
The FTB was original to the engine.... personally I think this was the cause of the lean readings, but I am no mechanic.....
Also cleaned the Toyota Air filter, double checked the intake pipes for any leaks after the MAF.

I did notice the post-cat 02 sensor wire making a slight contact with the drivers side CAT, but after further inspection the wires were not compromised....

Codes were deleted manually and after about 100 miles all seems fine.....

Good luck...

FTB? Throttle body? Sorry lost me on that lingo?

Throttle body is new as well, as is the air filter....these trucks love those mass air flow codes man. Air filter is new, intake is perfect. It’s like it’s just finding air somewhere.

Recently had the exhaust re-done too so im not thinking it’s that just yet

 

[MANUCHAO]

Throttle body?

Yes...... check for vacuum leaks on your air intake... and in around your exhaust manifolds and cats.....

Other than running a scanner that gives yah live feed.. that's all i got...

 

[morganism]

does that have a " Readiness Monitor Drive Pattern" that you need to reset?

Toyota Service Bulletin EG003-02

You need to pull neg cable and turn key to ON a couple times to drain computer.