Hello and thank you in advance for any help.

Problem: Rough idle and engine light with codes:

YOUCANIC Code Reader: P0300, P0350

Background:
2002 E320 Standard (no 4matic)
272K miles
New wires and new plugs
Swapped coil on 5 and reset code and problem still exist
Pulled plugs and both of cycl 5 were fouled. See pic
wires looked good.
Other cylinder plugs were fine...
Put new plugs in cycl 5 and reset code. same issue
Car seems a hair more responsive.

Next steps?
Do I swap and injector?
Or?

Attached Thumbnails

 

Try another injector.

__________________
Jim