CEL Light (Advices needed)

[superpat]

First thing let me apologize for any speeling or grammar mistake
my firts langage is not English...


My cel ligth whent on couple days ago its the infamous low fuel bank 1 code.

2 years ago the exhaust system was replace starting at the manifold (new everything 02 senser, catalystic concerter etc...)

i was told to put only 94 octane and plus and the cel should not go back. This was BS because in the owners manual it says to go with 87 and plus.

Now i know that i have a leaking manifold gasket . Could this be a cause of the cel ? I doubt that the o2 sensor is defective since its only 2 years old.

Also i read post about gas smell when walking next to your rig. Could my canister be the cause of the cel light ? I also change my gas cap and sandblasted and repainted the fuel filler neck

Also the same guy that said to go with premium fuel said that a spark plug could be defective, but yet again i dont belive him because if a spark plug would not work properly i would get a missfire code not a low bank low fuel one

Anyway please help me shed light on this mistery

 

[CJF]

1) Year of your rig.

2) Exact code number that was thrown.

 

[superpat]

1996 FZJ80 4.5L

p0171 fuel system lean bank 1

 

[CJF]

Now i know that i have a leaking manifold gasket . Could this be a cause of the cel ?

Intake or exhaust?

If intake, then, yes, it could be the cause.

If exhaust, then I dunno.