S60 2004 Car stalls with no warning

[Pmongii]

Car ran fine today no problems at all. The Check engine light is bugging me still being on, but this was on going before the stalling. So I drove to a local shop and asked if they can read my codes. No problem, was amazed as Volvo wanted $99.00 to do a simple code check, well it came up catalytic converter. I thought here we go $$$$. But to my surprise I was told that on my 2004 S60 Volvo the catalytic converter is porcelain, and that the dust travels out and not in, so I don't need to do anything. I just have to live with the light going on and off. Can anybody confirm this. I've checked other posts but haven't found anything on this issue.
As far as the stalling and other issues, all is good. Fuel pressure sensor fixed it.

[oragex]

It perhaps means the cat converter doesn't work properly to reduce emissions which is strange at 100K unless there was a lot of poor combustion who clogged the cat. Checking the spark plugs appearance could be an indicator on how the combustion goes.

Depending what the mechanic said it can also be a failed O2 sensor which is quite rare and doesn't matter, it only measures how well the cat converter works.

Side note, with a car these miles, going to a strip club would indeed prove less expensive than a visit to the main dealer. They are worst than sharks considering the remaining value of the vehicle.

[NOVA_Volvo]

Hi everyone, (Please read all the way, you will save money
I have had this problem (car stalling during drivning) for 4 years and it usually happens when the weather is hot (temperature range 80+ to 100+F). I have been puzzled for the last four years and have spent about $700 (reseting the SRS Air bag Service Urgent twice at shops, changing fuel filter, reloading S/W at dealership and finally purchasing the Volvo code scanner from Ebay). After reviewing tons of information online I have come to conclusion that it is the CEM (Central Electronic Module) that causes this issue due to not being able to handle excessive heat. (BTW, There are companies built around the issues of CEM and ECM (Engine control module). I have fixed this issue by just spending $5.00. YES, That is true.
Here is Why and How?
Please bear with me, I will have to explain the issue and then discuss the resolution:
Issue: You hear a load thud sound or some sort of noise while driving, this is when the first stalling happens, then the DIM (Driver information module, Dash board) acts up, within 1/2 of mile or less more stalling happens and your DIM goes crazy with multiple issues "SRS", "Brake Failure", and finally the Dash board (DIM) dies (all gauges and lights). Now you are really worried and you pull over, if you make a turn at slow speed while pulling over, the car die. after a few minutes you cannot even turn the car on. You will have to wait for about 10-15 minutes. You turn the car one and every thing is fine, but the "SRS Airbag Service Urgent" message is on. BTW, I had many different variation of this issue and how the car dies has happened to me. The sad thing is that Volvo as a company and its dealership is well aware of this issue and asks for ~$1400 to replace the CEM. The other shops just want to take your money and reset the messages and will ask you to spend money on fuel sensor, MAF sensor, crank sensor, this and that since they do not have a clue.
Root cause of the problem:
If it really happens during hot weather it could be related to poor air circulation on important components of the CEM unit. If you can take the CEM out (videos available on You Tube on how to take out your CEM), then you could clearly see that there is a common heat sink is used on two parts that dissipate heat and this method of heat dissipation in very poor. If the heat cannot be removed from these devices, they will heat up more and electronics with loaded firmware will not work well. The CEM communicates with many electronics of the car and if the communication breaks down due to malfunction of the devices due to excessive heat you will have the stalling problem.
How to fix it yourself:
This may sounds funny or unusual, but it is doable and I have fixed this issue after four years. Here we go >>> There is an air register on the right side of driver leg where the cool or warm air blows on your feet. Once your remove the right and upper panel, you will see that you could run a hose, yes a hose from the inside of register and bring it to top the CEM module, You can buy the soft 3/4 hose from home depot (less than $5.00), you could route the hose under the panel (right in front of driver's knees) and bring it over the CEM unit which is located right in front of your left knee. BTW, the CEM and the hose are all hidden under the panels. So, we you turn the car AC on, the air flows through the hose on top of the CEM and keep the devices cool. You will never see this problem again. Important note: When you turn the car on, let it run for 1 minute or so while the AC is on and blowing on the lower section (feet area). The cold air will travel directly through the hose on top of CEM and you will never have this issue.
Or, you could send your CEM for upgrade and installation of heat sink to shops who advertise for such service and it cost hundreds of $.
Note: My car is S602.5Turbo AWD, it has 112000 miles and it no longer has this issue. Good luck.

[VolvoS60SC]

I may be barking up the wrong tree here, but something similar happened to me last year- it was on my S70 so different car. I did some work on my car and it was running great....where I was in town, there is a no-name gas station with cheap gas...I needed gas so I filled up...then about 1/2 a mile down the road, I got some stumbling and a stall... got it running again and got it home... similar issues continued- on again...off again. The only thing I could figure out is I bought some bad gas and that was after a considerable amount of tinkering (just like you).... called the gas station- of course they denied any wrong doing. I seriously thought it was bad gas so I called the State Inspector's office. They sent a crew down the next day and ran a sample of the gas from this station. It turned out, that they had like 15% water in their gas and the octane rating was off as well (premium wasn't premium). I got my money back on the bad gas but that was it (certainly didn't pay for my time or the additive I added to my tank to try to dry out the gas)... I drained what I could out of the gas tank through the schrader valve on the fuel rail into some containers and have been using that in my cheap lawn mower...put gas stabilizer in the tank when all this happened- it helped some... after the next fill up with good gas, my problems were finally all gone!! So, to make this long story short, where did you buy gas last? Could it be bad gas? They are starting to mix gas strangely at some stations with summer coming on and if it's been raining a lot in your area, that might be another reason to suspect something like this.

Of course it could be a vacuum leak...unmetered air into the system. Do you have a turbo car? the 2.4l does't really tell me although maybe it should. A MAF sensor could also be going bad- easy to clean at least- just spray with MAF cleaner and let it dry- don't touch the sensor... Of course at MAF would usualy set a code. You said the CEL came on but no code? That's very odd...

I recently had the same thing happen to me with my 2007 S60. Now, if the gas gauge gets down to the red, it sputters and stalls, which makes me think the water is on top of the gas in the tank and only gets sucked into the fuel line when it gets low. Once I fill it back up, it's good to go again. I'm going to check out getting the "additive" you used to dry out the gas.