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P0171 System too lean - Dipstick not pushed all the way

5K views 3 replies 4 participants last post by  avenger09123 
#1 · (Edited)
So I added a bit of engine oil the other day and then the CEL came on with a code P0171 - System too lean. My car is a 2005 s40 2.4i with 160k miles.

I thought it may be the oil filter housing acting up, although I've read this isn't too common on 2.4i engines. I also didn't feel suction when opening the oil filler cap.

When taking apart the air intake, I noticed the oil dipstick was not pushed all the way in. Damn whoever was in there last (that would be me..)

Pushed it back in, cleared the CEL, and everything seems to be back to normal.


Anyone with some more insight? Could this be an early warning of PCV issues? Should I replace the oil filter housing sooner rather than later?
 
#3 ·
The crankcase pressure is not negative with the dipstick out. It has an o-ring for a reason! The PCV won't operate properly without it.
 
#4 ·
So I added a bit of engine oil the other day and then the CEL came on with a code P0171 - System too lean. My car is a 2005 s40 2.4i with 160k miles.

I thought it may be the oil filter housing acting up, although I've read this isn't too common on 2.4i engines. I also didn't feel suction when opening the oil filler cap.

When taking apart the air intake, I noticed the oil dipstick was not pushed all the way in. Damn however was in there last (that would be me..)

Pushed it back in, cleared the CEL, and everything seems to be back to normal.

Anyone with some more insight? Could this be an early warning of PCV issues? Should I replace the oil filter housing sooner rather than later?
System too lean indicates either you have on O2 sensor going bad, or you have a clogged air filter and it can't pull more fuel out to compensate, clogged injectors (unlikely), etc. Can be some other things but mostly I've found those are the two big culprits.
 
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