Anyone know what's causing these code to pop up P0171 and P0174?

 

Those are lean codes for bank 1 and 2. Most likely you have a gasket leak thats letting in unchecked air to the cylinders causing you to have a leaner than intended burn.

Do you have idle issues? Usually they go hand in hand. Use some carb spray and spray all the intake seals and gaskets and see if you notice a difference in engine speed. The air flow tube commonly develops cracks and breaks. Check for that also.

 

[QUOTE=musiclevelz5;15658576]Those are lean codes for bank 1 and 2. Most likely you have a gasket leak thats letting in unchecked air to the cylinders causing you to have a leaner than intended burn.

Do you have idle issues? Usually they go hand in hand. Use some carb spray and spray all the intake seals and gaskets and see if you notice a difference in engine speed. The air flow tube commonly develops cracks and breaks. Check


Could it be the weather change. Because the same code pop up around this time last year too. Took it in and they jus turn it off. Never came back until a couple days ago.. or could it be my o2 sensor?

 

The O2 sensor has its own set of codes when it does go bad. That is unlikely to be a bad O2 although you can change them if you want and see what happens.

 

Okay thanks. Man idk what could it be. But I guess I'll give it a suggestion for the dealership to take a look at the gasket stuff. Lol

 

i had the same two codes on my 04 TL. it comes and goes, i changed one of my o2 sensors which was in pretty bad shape but it popped up once and went away. make sure you are using the correct grade of gas for your car..as ive been told the use of incorrect gas can cause these codes to pop up.
hope that helps

 

P0171 and P0174 - OBD-II Trouble Codes