running lean at idle p0171 how long can i run like this for?

[ian2328]

ive been trying to hunt this code for a month before i finally got a smoke machine and found the leak in my intake gaskets. visually, it just "seeps" not billows smoke. already ordered oem gaskets but they might be here too late for me to work on it soon. the weekends are the only free time i get to work on the car and it worries me that its not running right. engine sounds fine, no pinging or rough idle just worse gas mileage. check engine light is off (chatgpt tells me the ecu has been able to compensate with more gas) but i verified the lean condition with a scan tool 19.5-30% LTFT short term is normal range, only lean under idle during normal driving it doesnt run lean. cooling system and ignition are in good shape.

thanks!

 

[Posty]

Often when I get your symptoms it's a dirty MAF sensor. I'd clean it with CRC Mass Airflow Cleaner, reset ecu & check trims again to see if it made a difference.

 

[ian2328]

Often when I get your symptoms it's a dirty MAF sensor. I'd clean it with CRC Mass Airflow Cleaner, reset ecu & check trims again to see if it made a difference.

cleaned maf twice while hunting the code, unfortunately didnt make a difference which made me get a scan tool but at least now my maf is clean lol

 

[phattyduck]

i verified the lean condition with a scan tool 19.5-30% LTFT short term is normal range, only lean under idle during normal driving it doesnt run lean.

So, find the vacuum leak... When vacuum in the manifold is high, it is pulling in unmetered air from somewhere. The fuel injectors are 'air assist' type, so there is a large vacuum line to those that run with the fuel rails that provides much of the idle air flow. If that pipe isn't hooked up to the intake pipe, it'll do what you are experiencing.

-Charlie

 

[ian2328]

So, find the vacuum leak... When vacuum in the manifold is high, it is pulling in unmetered air from somewhere. The fuel injectors are 'air assist' type, so there is a large vacuum line to those that run with the fuel rails that provides much of the idle air flow. If that pipe isn't hooked up to the intake pipe, it'll do what you are experiencing.

-Charlie

first sentence of my post.....? my question is if i have to worry for a week or two if i cant get to the gaskets due to shipping since the lean condition doesnt trigger a CEL

 

[phattyduck]

first sentence of my post.....? my question is if i have to worry for a week or two if i cant get to the gaskets due to shipping since the lean condition doesnt trigger a CEL

Dabbing a bit of RTV where its leaking will take care of most/all of the leaking, at least temporarily - and should take just a few minutes. I'd also do a quick bolt check to make sure the nuts/bolts are tight. Those gaskets are pretty robust, so I'd suspect contamination or loose fasteners.

-Charlie