First off this is a stock (except for the chip) '01 that's driven daily. Coupla nights ago I noticed a slight rattle at WOT, I thought it must of been some crappy gas so I ran that tank out and refilled. Last night the rattle was not so light and really loud. I immediatley shut it down and limped it home.
Where would you guys start looking? It's never done this before and I won't put it under load until I find out what's causing it.
Thanks
Greg

 

Pull the chip and see if the detonation is still there.

 

how old is the fuel filter???

 

I'd be looking at the filter too.

Jody

 

I have no idea about the filters age. I'll change it this week.
Truck has 55k.
Greg

 

Well the filter looked to be the original, so I changed it out. I'll know if it still detonates tomorrow. I'm figuring that 56k on the filter was the problem.
Thanks for the advice.
Greg

 

my 04's fuel pump went at 8000 miles, check your fuel pressure.

 

I would bet it's your fuel filter!

 

Fuel Filter - maybe MAF is dirty.

 

Like the everyone said, the fuel filter is probably the culprit. My tuner suggests changing it every 7,500 miles.

Also, I would only run Amoco, Citgo, or Shell gas here in the S.E.
These fuels are good quality and are best to keep detonation away.

 

Even if the filter solves it, check your plugs. You may have some electrode damage from the detonation.