Code P0171 Too lean 04 S60

the65dartguy1 · Post by **the65dartguy1** » 09 Mar 2018, 13:01

My 04 S60 NA has been tossing the P0171 code lately. I have read here but my symptoms do not match. The car doesn't stall, starts, runs, drives and idles fine. It also passes the glove test. Car has approx 153k miles on it. I do not know when PCV was last serviced but I sincerely doubt very long before I got it. ( was owned by a wealthy family who took it to the dealer religiously)

Any thoughts/ ideas??

One note, this only seems to have happened in winter. if i remember right it did this briefly last winter too but it went away on its own. All the hoses and vac lines look to be good with a quick visual inspection.

Georgeandkira · Post by **Georgeandkira** » 09 Mar 2018, 13:17

P0171 = a lean code of sorts.
The "real" Volvo code might be more helpful.
I say this because I have the same code recurring in a 1999 Saab 9-5 and it's driving me mad.
The code alternates with a P0445 code.
Out of desperation I'll replace each inch of EVAP hose come Spring.

the65dartguy1 · Post by **the65dartguy1** » 09 Mar 2018, 14:39

Yeah, my VIDA is on the fritz right now or I would use that.

Post by **jonesg** » 09 Mar 2018, 17:11

the65dartguy1 wrote: ↑09 Mar 2018, 14:39 Yeah, my VIDA is on the fritz right now or I would use that.

I had a lean code that I eventually fixed by changing to full synth oil and new filter.
Low oil pressure was causing cvvt lag.

Post by **abscate** » 09 Mar 2018, 18:42

A visual inspection of vacuum hoses is near worthless

See if your Short term fuel trim tends high at idle to confirm a vacuum leak

Post by **mrbrian200** » 09 Mar 2018, 21:20

Runs lean at idle, mainly in winter. Possible symptom of failing electronic throttle body (bosch type, internal gear wear). If if passes a smoke test yet is running lean at idle, it could be the throttle plate not closing all the way. On my car, in VIDA I could tell that the ECU could see that the throttle plate wasn't closing all the way (6-7% above the idle stop position), but was either treating it as sensor tolerance/adaptation or was cutting the fuel back to prevent high idle/unintended acceleration. However, it never displayed a code specific to the throttle body. It just displayed fuel trim DTCs, and as the problem got worse, MAF low signal DTC.
Keep this in the back of your head should you rule out everything else, it could be the throttle body.