Have a question to a problem that evades a resolution.
1998 S70 T5 uses only one coil for all cylinders.
During high excelleration cylinder #4 misses ever so briefly between 3-4 gear and 4-5 gear. Causes engine light to come on. Error specifically states it is cylinder 4. I have reset the engine light and can cause the miss to occur again. At no other times will Cylinder number 4 fail to fire.

Any ideas what might be causing this?
Thank you

 

Last Full tune up?

 

+1 to what Tech said.

Like you said, you've got an issue with cyl 4; what I would do is:

1. Pull the plugs; compare plug from #4 to the others; does it look different?
2. Ck compression on all cyls; is number 4 low compared to the others?
3. If above looks OK, then I would focus on ignition specifically; could be a bad plug wire (replace the whole set, OEM) and/or bad cap or rotor. If it's due, just replace all this (part of major tune up).
4. Beyond that it could be a faulty injector on that one cyl; less likely than above though.

Let us know what you find.. good luck.