random misfire cyl 3 only at peak boost

[2K1Ultrasport]

I used had more prominent misfires in multiple cylinders but those seem to have gone after the G28 replacement.
while i was pushing it this morning as a test, it recorded an intermittent misfire in cyl 3.
the misfire is very slight (hesitation) and only happens at WOT and peak boost.
plugs or coil?
car is 2001 1.8t.
running k04 hammer with all the other goodies (except upgraded intercooler)
swapped the coils to bolt in type and currently running on PFR6QE plugs (have some BKR7Es ready to get swapped in when needed)

also had a failed cat in readiness.
how many miles does a cat usually go before clogging?

[k0mpresd]

try plugs first.

my car had a very similar situation. it would only misfire at full boost/high rpm. we swapped plugs with no avail. swapped coils from the original hitachis to the push down coils. misfires cured. no other changes were made.

failed cat could be o2 sensor related.