Hello, I 'm new to the forum and was wodering if anyone has had a P0171 code before on a 2001 XG300 before? It says bank 1 is too lean. Thank you, Andrew

 

Are you planing to correct it yourself or take it to the shop? Mine pops the check engine light when I fill up with non-brand fuel. You might just change your brand first and see if it clears up.

 

Yes, I'm trying to fix it myself. I have used several different types of gas and I cleaned the MAF sensor too. So far no luck. I think the MAF might be bad, I'm only gettting about 17 MPG city and 21 combined. I don't think the motor is running lean with those numbers. Do you know which O2 would set off the lean codes? It could still be a O2 sensor. I'm also going to spray carb cleaner around the gaskets and vacuum lines to see it I have an air leak. These two codes suck! They are to vage.

 

sounds like its an o2 sensor to me it will be an upstream one (before the cat). but cannot remember which bank is 1 sorry.

 

The codes are telling me that bank one and two are running lean. I have seen codes P0171, P0174 and P0159.

 

If I recall a p0171 is a fuel trim lean code. This is normally caused by a bad mass airflow sensor or a vacuum leak. Either the maf is sending a faulty signal to the pcm or the computer is trying to comoensate for a vacuum leak. You would have to hook it up to a scanner and check the data on the maf to see what signal the computer is seeing and to check that the mafis reading the amount of airflow through the maf

 

i just got my car fixed from Hyundai and the it cost be $1000!! The MAF was bad and the intake was broke. i guess there is a butterfly assembly in the middle of the intake that adjusts the airflow after the throttle body. I thought that is what a throttle body does? The mechanic said the gear breaks off and the butterfly assembly and it doesn't work.

 

That sounds like it could be a o2 sensor or mass air flow sensor , I know on my toyota you can spray the mass air flow sensor with electronic cleaner and it will cure it. Most times it is dirt on the sensor which is a wire element.

 

My check engine light came on and I got it read on an OBD II and it came back as a "PO455-EVAP Emission Control System Leak (Large)." Car-2002 Elantra seems to be running fine at this time. However, there is an audible "vacuum leak" that the parts guy pointed out when the hood was up coming from the rear of the engine area. Any hints or solutions would be appreciated. THANKS