I have a spark knockin
97 4.6 4x4 w/ 189k miles.
Its not the brand of gas
its not the plugs
its not the air filter

I was woundering what ya'll thought about trying some octane boost before trying 89 or 93 octane gasoline?

 

fuel filter pluggage, & check timing. does it only happen under throttle, or steady load at 2000 RPM?

 

It has been knockin before i had the fuel filter replaced last year, and after

timing is computer controlled you can't mess with it i believe

it always does it under hard throttle ( 3750 rpms on up)

it sometimes does it cruisin on the interstate at 1800-2100 rpms (60-73 mph) (usual cruisin speed)

Its been a while since ive towed the 17' center console boat(my dad usually towes that) i dont remember how it reacted then
The spark knock is not any different when i towe my jet ski.

 

Have you ever cleaned the MAF sensor?

 

If the MAF is the sensor imbetween the air filter and Throttle body, it is perfectly clean and looks brand new.