Hello, I have a 2007 S40 2.4i and am stuck with the P0171 code. I have tried cleaning the MAF sensor and replaced the MAP sensor with no luck.
I looked for a vacuum leak with some soapy water but did not find anything noticeable. I do have my scanner freeze frame and was going to see if anything stuck
out to anyone on here. This code registered with a warm engine not long after resetting the code. If anyone has an idea I am looking for any answers.
It's inspection time and this is extremely frustrating. Thanks guys looking forward to any responses.

DTCFRZF P0171
FUELSYS1 OL-DRIVE
FUELSYS2 N/A
LOAD_PCT(%) 13.3
ETC(C) 86 DEGREES
SHRTFT1(%) 0.0
LONGFT1(%) 16.4
FRP(kPa) 381 (PSI) 55.3
MAP(kPa) 21 (inHg) 6.2
RPM(/min) 1837
VSS(KM/H) 85 (mph) 53
SPARKADV -13
IAT(F) 86 (C) 31
MAF(lb/min) 0.665 (g/s) 5.03
TP(%) 14.5
RUNTM(SEC) 468
EVAP_PCT(%) 0.0
FLI(%) 27.1
BARO(kPa) 99 (inHg) 29.2
VPWR(V) 14.667
LOAD_ABS(%) 2.7
EQ_RAT 0.996
TP_R(%) 4.3
AAT(c) 3 (f) 37
TP_B(%) 31.8
APP_D(%) 7.1
APP_E(%) 7.8
TAC_PCT(%) 4.7

 

I'd probably invest in a smoke test. the air leak could be in a hard to find vacuum line (like going all the way back to the charcoal cannister ), in the intake tubing etc. It could also be an exhaust leak - any sound or air coming out around the manifold or flex pipe. Not sure if your model has an idle air valve or if the ETM takes care of that directly. Any other symptoms - bumpy idle, surging at various RPMs? Only other thing I can think of is fuel pressure being a tad low - but I'd suspect you'd see some power loss, particularly at higher RPM.

 

The car drives fine. Haven't had any issues other than sometimes I gotta turn it over for about 5 seconds before it fires up. The rpms stay steady. The code doesnt hesitate to come back on after resetting it. Usually right after giving it some gas. I may look into a smoke test. Where do you normally hook up to when doing one?
Also is it normal for the spark advance to be negative?

 

I'd just pay a shop with a smoke machine but there are some vids on Youtube (including one by RobertDIY) which shows an idea on how to make your own and how to feed into the intake. As far as the timing advance number - that's controlled by the ECU so I wouldn't read too much into it. If your camshaft or crank timing were off, you'd get a check engine light.

 

I had the same fault code and changed the O2 sensor, MAF sensor and the inlet manifold gasket.
The fault came back each time within a few miles. Eventually I found a small hole in the crankcase breather pipe. I temporarily taped the hole and ran the engine. It was pretty obvious that the PCV housing was faulty as it made a loud howling noise. It turned out that the hole was drilled into the pipe to disguise the PCV problem but threw the emissions out. I would check all hoses and try spraying carb cleaner around the piping and manifolds while the engine is idling and see if there is any change in the engine note.

 

Hi, I'm having a very similar problem with my 2008 Volvo S40.
How did you fix it?

 

I apologize if this isn’t allowed but I don’ t know how else to find S50T folks
This car is well maintained new complete headlights, radiator, starter, alternator, brake lines AC runs cold.. lot of new parts spare filters and parts blown head gasket will overheat in about 40 min / 40 miles. Roof racks etc. Hate to junk it…North Florida Duaneo43@yahoo