hi guys long time p0171 code is back, do you think its the maf sensor again i noticed the car at idle the Short term trim jumps right to 25% as soon as i idle and when i drive it goes back to normal trim levels, does this sound MAF related?

 

check for vacuum leaks first.

 

no vaccum leaks that i can see, however i did notice on my obd 2 scanner that when code p0171 came on turning on my check engine light, at the same time my scanner is report "evap not ready" but all the other componets are ready, is there anything evap related to po171?

 

Hey well found my problem the brake booster hose was bubbling and cracking up and caused a vacuum leak. Replaced with a like new condition junkyard brake booster hose, check engine light off no more rough idle.

 

In almost all cases of P0171 it is a vacuum leak. Good job, mazpro00!

 

You got lucky, mine was actually an internal leak inside the booster!
I got a good one from the boneyard!

WOW, I just looked at my first post, post #6: "You also don't need an external vac leak to have a vac leak. You could have an internal vac leak from your brake booster. Pinch off the line to see if it idles better."
Guess i was pretty close!