i had a similar issue some time ago while cruising in 5th going up hill. From time to time it still happens to me with pump gas. do you have a wideband to read air fuel ratios?

With the throttle position at a low percentage, low'ish rpms, and a large load on the engine, what tends to happen is that the engine will run lean and will lightly knock. when my CEL came on i could never hear or feel the knock, i would only see the light flicker.

you running dsmlink or maft?

no I've got open port. And my wideband is broken maybe I'm getting bad gas.

id say fuel pump or reg problem. if you can log knock then id check that, but having no wideband sucks.

im on the bad gas boat. where you buy and how consistently

I get 93 at a surefine. Fill up once a week. Maybe I'll try a tank of eth free from kwikfill. What ever it is maybe it will be an excuse to get those fuel upgrades I've been procrastinating on.