2000 Ranger Idle problem (CEL)

[Ranger2000]

Hi All, new guy here, just bought a 2000 ford ranger with 102K miles about a month a half ago . Recently the check engine came on and it had the following errors P1131 and P0171 I believe the first one is "main Cntl fuel air metering" and the second one was "system too lean bank 1". Took it to the shop and they replace the o2 sensor bank1. About a week later it came back on again with the same error, luckily for me there was a guy that work at advance auto parts (where i got the codes read) that had the same vehicle and he recommended that I clean the MAF sensor. I clean the MAF sensor and the check engine light was off for about 3 days then it came back on with the same codes. Is there anything else i could look for that would cause these codes, I tried looking for leaks in one of the hoses but I couldn't find any. Any ideas as to how to solve this problem would be appreciated.

 

[jcam8]

i worked at a quick lube for a few years and more often than not it seemed that the "system to lean bank_" was not enough pressure in the fuel system.....e.g. the customers left the fuel cap off after they got gas. i'm not sure why this caused this code but it did. so i'd maybe try replacing the gas cap, but thats kinda a shot in the dark. the other code, i'm not sure what that means. i'd type the code right into google and look around. that always helps me when my check engine light comes on.

 

[locovaca]

i worked at a quick lube for a few years and more often than not it seemed that the "system to lean bank_" was not enough pressure in the fuel system.....e.g. the customers left the fuel cap off after they got gas. i'm not sure why this caused this code but it did. so i'd maybe try replacing the gas cap, but thats kinda a shot in the dark. the other code, i'm not sure what that means. i'd type the code right into google and look around. that always helps me when my check engine light comes on.

The fuel tank is pressurized so leaving the cap off causes a vacuum leak. Follow the hose from your charcoal canister sometime...

 

[99supercab]

from my experince with my truck the DPFE sensor or the IAC valve