Rough idle, stall

[2006 Volvo]

Hi,

This started yesterday. I went to accelerate, the engine backfired once then shuddered, ran rough for a bit but then was ok. Got home, parked the car and about 1/2 hour later went back out to the car. It started right away, I drove off and it stalled. No Check Engine light came on. Parked the car for the night.
Next morning, started the car, it revved up to about 1500, dropped down to about 800 then stalled. Checked for error codes - nothing. Did some research. Replaced the plugs, air filter, fuel filter and cleaned the MAF (with MAF cleaner).
Now things are much worse. It is very hard to start, only runs when revved up to 2000+, does not idle at all. Check Engine light is now on. Still no error codes.
Please help.

P.S. Should I have primed/bled the fuel line before trying to start? Do I need to bleed the fuel rail? The fuel filter I put in was longer than the original. Does this make a difference? The filter also did not have an arrow to indicate the direction of flow. I placed it in the same way as the original.

[2006 Volvo]

Easily started the car this morning. Lots of fuel to the rail. Disconnected the MAF sensor. This made no difference. Took out the plugs and noticed four were black, one still shiny like new. Is this now a coil issue? Engine runs but not smoothly. Check engine light is still on. No error codes.

[JRL]

Probably (and you probably should have used a Volvo fuel filter) but that should not aggravate this problem.

What do you mean CEL is on with no codes?
You can't read an 2005 and newer with an older code reader, it must be able to read a CAN networked car. (they exist)
Of course you have a code, you're just are unable to read it!
You need to understand your Volvo, right now you're just spending a lot of time and money throwing unknown parts at it for no good reason!

[2006 Volvo]

Probably (and you probably should have used a Volvo fuel filter) but that should not aggravate this problem.

What do you mean CEL is on with no codes?
You can't read an 2005 and newer with an older code reader, it must be able to read a CAN networked car. (they exist)
Of course you have a code, you're just are unable to read it!
You need to understand your Volvo, right now you're just spending a lot of time and money throwing unknown parts at it for no good reason!

Bought the code reader a couple of years ago. Engine needed new filters anyway, so I figured it was worth a try. Now my dash message says "Engine System Service Required".

[JRL]

Did it actually read any codes before?
You can buy many today that can't read a Volvo, it MUST be able to read CAN, most do not.
Time to take it to the dealer or a seriously good Volvo indy shop