Intermittent P0171 and p0300

[HiHoeSilver]

I looked at my short fuel trims this morning when i get on it it bank 2 shows higher than bank one

What kind of numbers are we taking about?
How high are your long terms?

When you get on it do the short terms go negative at all, or do they go higher than they already are?

 

[chevy1500]

What kind of numbers are we taking about?
How high are your long terms?

When you get on it do the short terms go negative at all, or do they go higher than they already are?

The short term on bank 2 goes to 7/8 and bank 1 goes to 5 and it subtracts alot

 

[HiHoeSilver]

The short term on bank 2 goes to 7/8 and bank 1 goes to 5 and it subtracts alot

Your 0171 is a lean code, so the upstream sensor is seeing too much air or not enough fuel. The computer is correcting by pouring more fuel. It's forcing the long term trims up and setting the code.

As you increase RPM you are in less and less vacuum, so your short terms are going to move one way or the other.

If the short term trims are going down as you get on the gas, you have a vacuum leak somewhere.

 

[chevy1500]

Your 0171 is a lean code, so the upstream sensor is seeing too much air or not enough fuel. The computer is correcting by pouring more fuel. It's forcing the long term trims up and setting the code.

As you increase RPM you are in less and less vacuum, so your short terms are going to move one way or the other.

If the short term trims are going down as you get on the gas, you have a vacuum leak somewhere.

i wonder where could it be i did the carb fluid trick no change i changed the intake gasket no change but youre right about the vac leak somewhere be cause it feels like it at idle

 

[HiHoeSilver]

i wonder where could it be i did the carb fluid trick no change i changed the intake gasket no change but youre right about the vac leak somewhere be cause it feels like it at idle

It's possible to have one big enough at the exhaust manifold to cause some bad numbers, but i don't see it causing the misfire code.

 

[chevy1500]

It's possible to have one big enough at the exhaust manifold to cause some bad numbers, but i don't see it causing the misfire code.

It threw the 0300 code only one time so no more misfires all im dealing with is the shaky idle and the intermittent 0171

 

[Big Mama]

Still sounds like an injector or two?

 

[chevy1500]

Finnaly have the freeze frame and im still stomped smh

 

[Tonyrodz]

Sub'd

 

[M1Gunner]

HOLY $@&! Your long term FT B1 is stupid high about maxed out. There’s your problem. It’s having to dump fuel to B1 to compensate for B1 lean condention. So think about things that will only effect one bank... intake manifold gasket etc.