NO.
Even if the knock sensor was bad, it should not ping, ONLY on a cold start up at WOT, and vanish completely in 3 minutes when it is hot.
I have never seen any vehicles do this in my life, on a cold start up. Only when they were over heating and about to blow up the radiator, or already had.
Non of the logical known possible items I am aware of can cause it do this on just a cold start up.
I can't make it ping no matter how hard I try once the block temp is up over about 160-180 F.
IAT and CTS are good, O2 sensor good. Fuel pressure good.
It reminds me of using cheap, low octane gas on high compression 70s car. But I don't recall that being an issue on a cold engine at 70-100% WOT either.
RPMs/trans gear is normal. If it was carbon it would still do it hot.
If it was mechanical wear timing (chain), I doubt it would be just a cold start issue? I have found others with the problem that have it had it for ages, but none of them have solved it either.
Thought someone in the crew here might have run across it.
If it was a cold O2 sensor, it should be running rich in open loop, and have no chance to ping? Unless the spark is way too early, but why would the spark be way too early only when cold in those first few minutes?
Only does it cold, under load in gear at >50% of WOT. It should be ignoring the O2 sensor at high throttles anyway?
Renix?
Hate to be Captain Obvious here, but maybe the knock sensor?