While driving today i get a cel so i stoped at the autozone to scan it and see what up with that so i get P0171 System Too Lean (bank 1) car runs fine no problems. I checked tho hose to see any crack but i dont see anything. Any advise where should i start? also i did do research on this.

 

Most likely a MAF, primary O2 sensor, or vacuum leak issue.

 

when its MAF or O2 sensor it does not show which one is it?
I did check it again reset the Cel Light but still came up.

 

I'm having the exact same issue on my 02 1.8tqm. Runs fine, new PCV, new fuel filter. No detectable vac leaks and no change when I disconnected the MAF and took it for a run.
It idles flawlessly and doesn't seem to be down any power at all.
I'm lost.

 

you can welcome another P0171 member here.
had 2 codes so I replaced PRV and now only P0171 is left. I have no boost gauge yet so cant see if its vac or maf or o2
car seem to run ok for now but I feel that its somewhat underpowered and gas milage could be better.

 

have u looked at the check valves. Alot of times those get corrided letting out interminting leaks. I think there is 5 or 6 on the 1.8 Should be a diagram floating around this site.

 

i glanced around and found nothing corroded. My engine is pretty clean to be honest for 60k

 

you ever figure out what it was? I'm having the same issue

 

Yes i did, i was getting air in the system from the maf, my intake silicone had pop out which was causing the problem. i did a vacuum test and found air coming in.
Do check all your vacuum lines vic_13 just to make sure is not that and then check maf and o2 sensor

 

how would one go about doing a vacuum check