Will start but won't stay running Topic is solved

[abscate]

185k on the First Generation MM Electronic Throttle is pretty good life, so that is suspect.

Yes, you do need the right tools to diagnose, or spend money shotgunning parts. Modern cars can't be diagnosed by symptom, systems are too interconnected.

If you have a vacuum leak, for example, unmetered air will make it run rough. Unplugging the MAF makes the car run on a look up table , so it will run smooth. This does not mean the MAF is bad, fo course.

[Jabosborne]

I finally got a code yesterday afternoon; P0422. Of course I Google it and it state something about the catalyst threshold. I immediately assumed catalytic converter and contacted my mechanic to come and get my Volvo. After more research I realized it could still be a number of problems. I will try to keep everyone updated on the exact issue and hope this helps someone in the future. Thank you all so much for trying to help!!

[DrDan]

The P0422 is probably not related to running problems. It's thrown when the catalytic converter (monitored by the downstream O2 sensor) exhibits below threshold capacity to store oxygen. However, seeing that code very likely does NOT mean you need a new CAT. I've seen it twice on my car in 5 years, it disappeared on its own, and the car has since repeatedly passed emission tests with flying colors.

[abscate]

When were th e spark plugs last replaced? These are 30-50k lasting items depending on type

[93SCMax]

Now that your battery has been replaced, and the P0422 code revealed ( i believe not associated with your issue), you say it idles fine with the MAF disconnected, correct? When you reconnect the MAF, can you drive it or does it still not "get gas"?

The MAF can be bad if it idles correctly (unplugged), but does not run when connected. Please don't rule the MAF out at this point as this would be the next component I would want to eliminate as a source of your problem (if it still exists). You could have a bad electrical connection to the MAF (wiring or pins), the MAF "filiment" may need a good cleaning, or it may need to be replaced if it is original. I'd check the pins and wiring for corrosion and a good connection (plug snaps in place), clean the MAF (MAF cleaner from auto parts store), and if you have no improvement, I'd think about a junkyard replacement ($25 at a pick n pull). If these steps are beyond your comfort/skill level, possible get a new one...but only if it is Bosch or Volvo with the same part number.

Look at the throttle body only after the MAF, just due to cost differences. Start with the cheapest, most logical fix first.

And as a side note, I had exactly this failure mode and symptoms on my 2001 V70 T5 a few years ago. A junk yard MAF fixed it and has kept me running. I can't 100% say this is your fix/issue, but would go this route if you don't want to be taken to the cleaners by the dealer or your mechanic.

Good luck.

[XC90Dave]

Batteries go bad many ways, they may read volts on your meter but they can have a broken, corroded or separated internal cell which will not let current flow (amps when you start). Most auto stores will test your battery (load test) & tell you if it needs replacing. On the fuel pressure wrap a cloth under & over the fuel rail @ tschrader valve and push in center pin through the rag (like a tire tube valve) while help turns the key on. If the system is functioning gas will spray out (cheap man's test & no open flames . The 2001-02 SC60 2.4L does not have a PEM (fuel pump control module) so save time looking for it. On the end of the fuel rail there may be a FPS (fuel pressure switch). Check the fuse to the fuel pump (https://fuse-box.info/volvo/volvo-s60-2001-2009-fuses) #8 15A - 2nd from top on right side fuse box. Check the relay for the pump, here is a post from this site (viewtopic.php?t=74914). Hope that helps.