Hey guys,

I've had the service engine soon light on my truck for a while now and decided to throw on a scanner at school and figure out what's going on. Here's the codes, can anyone help me go about fixing them?

P0171 - System too lean bank 1
P1131 - Couldn't find what the code means... Anyone know?? I think it has something to do with passenger side O2 sensor
P0401 - Exhaust gas recirculating flow insufficient detected
P0174 - System too lean bank 2

Thanks for your help,
Brendan

 

What year/motor?

Might want to start with the EGR/DPFE. The 1131 is lack of switching bank 1 rear O2 I think. Also start looking for vac leaks.

Post what you're driving and we can help you much better.

 

2000 4.2 v6

 

I would check into the o2 sensor and maybe a new EGR. X2 on the vac leaks. Then clear the codes and see in anything comes back.

 

The codes 171/174 are due to the same fault. Likely an air leak some place on the intake hardware.
401 code is low flow on a routine test of the total EGR system.
Could be blocked ports behind the EGR, the EVR, or a vacuum hose leak and last, the reporting sensor DPFE.
The code 1131 will clear when the 171/174 fault is found. Leave the Ox sensor alone.
Good luck.