S80 2001 Check Engine Light P1171 P1181

[vegasjetskier]

According to VADIS, you won't have any software issues if you replace the MAF.

[paoli1]

HELP! I have exactly the same P1181 & P1171 error code problem. Nobody seems to know how to fix it besides replacing the MAF Sensor, which doesn't work. Does anyone have a solution for this yet?

[dcarlson12]

Here is a link to the trouble codes:
https://www.matthewsvolvosite.com/volvo- ... ble-codes/

and here is a link to the PPC list which you can use from the above list: http://www.ppc-diagnostic.com/codes/s261/

I had a problem with long term fuel trim on a 2000 Chevy Astro. It would actually set the CEL. It was a case of the fuel 'spider' having little check balls that go gummed up and allowed fuel to drip into the inlet manifold. I eventually solved the problem by using some STP fuel injector cleaner. It got rid of the gum which prevented the little check balls from seating properly. Not sure if this might clean any gunk which might be letting one or more of your injectors 'leak' fuel which would cause a rich mixture.
A garage told me that the oxygen sensor might need replacing. I did that before the STP injector cleaner and the oxygen sensor made no difference. I bought an Autotap scanner which hooks to my PC and actually shows how well the oxygen sensor was cycling. It proved that the oxygen sensor was not the problem.
I would give the STP fuel injector or some other fuel injector cleaner a try.
Let us know how you make out.

[Crito]

After replacing/cleaning your MAF or upstream/lambda O2 sensors you need to repopulate the long-term fuel trim data tables. Clearing the code alone doesn't do it. On my S80 I clear all codes, remove car battery, cross the terminal wires and let it sit over a weekend to drain any NiCAD or NiMHi batteries in the modules. After replacing car battery drive it for about 50 miles, mostly highway is fine. That seems to do it. If I just clear the code or don't drive enough after clearing the tables it reverts back to static/predefined mappings (instead of dynamic table data) and the CEL comes on again.


EDIT: Oh, and an old O2 sensor responds more slowly than a new one. So using a voltmeter and torch isn't really a valid test. But while the upstream ones are fairly critical the ones after the catalytic converter aren't (except maybe to emission testers in California). Some guys even plug the holes and let them dangle under the car. Plenty of oxygen outside. LOL