Wife's Volvo C30 is sick

On Thursday afternoon, my wife came home from Shopper's just down the street - just a short trip a few blocks .
Came home engine misfiring and very strong gas smell. Display showing "Try Slow Down or Shift UP". No engine codes?
Shut engine off. Took intake off, coil packs out and black sooty plugs.
All u tubers talk about coil packs being bad and to switch them around like 45minutes for me with the intake covering the coil pacs.
No one knows how to test them with a multimeter??
Might bite the bullet and order pacs and plugs.
I have had good prices and service for Bosch Parts from Parts Avatar on Shawson in Mississauga.
Any thoughts from others who had a engine conditions like this. Something else to look at?
Note: Wife mentioned is a female.
All reference to spark plugs as being black is only referring to temporary carbon deposit build up.

THANKS and Happy Easter.

That's weird that you don't have any codes.

Have you checked the C30 forum on Swedespeed for similar issues? If you were closer I have VIDA software to scan the car/computer.

https://www.swedespeed.com/forums/c30-2007-2013.101/

I get most of my Volvo OE or OEM parts from either FCP Euro (US) or Volvo Mississauga (and Rock Auto if/when they have the OEM part).

I forgot to say the C30 is a 2007 all original coils but newer spark plugs with 155k.
All sites "talk coils" but most of owners drop off after so don't find out the cure for engine trouble.

Injectors? Long story short, drove Civic through a flooded street by accident, hydrolocked engine. Got it back to running but had a cylinder 1 misfire according to a code reader. Rooted the problem to a bad injector. Swapped out and ran fine.

Coil on plug coils failing at that age / mileage is super common.

Can see that - I had a couple bad ones on mine around the 200K mark and then replaced the remaining 3 coils around the 240K mark (this is on the 2.5 engine).

OK, thanks for info, will start on coil pacs and plugs first.

Do all of the plugs look bad or just 1?

I think a single coil pack may be around $25-$30 on Amazon.ca

I think all 5 is like $112. Might as well change the plugs as well. At least its only 5 and not a v6 ;)

If it doesnt fix anything you may be able to return it back to Amazon without it costing you anything. Maybe read up on Amazon return policy a bit before ordering.

Do to required 5 on hand in stock requirement, I got 5 BOSCH coil packs from THE WRENCH MONKEY. Great price, plus on phone order with a smart human and PU at Carlingview Dr location. Just perfect. So wife should be off to the races very soon.
Thanks