why the rattle/chattering noise when feathering the gas pedal? HighRpm = louder.

Hey! Thanx for the response! So... Me and my buddy replaced the entire timing kit, thinking that would do the trick. I had it diagnoses at a nissan dealership. The chain was doing exactly what you said. Plastic guide gone, and chain grooving out the cover and stuff. To our dismay, it did not fix the issue. I did not change the oil pump. But, it runs smoother, and one of the noises went away... Timing chain noise. It is really bugging me tho. Thanks!

Here are some things that I did that actually changed the slugishness on my '96 D21. Check the harness that comes from the downstream o2 sensor to the side of the engine on the frame. Mine was overtightened which caused the sheathing to thin and made wires contact each other. Next, change the hose on the egr valve. It cracks but does not break so it looks intact. Next, clean out the fat metal line that comes from the charcoal canister behind the gas tank, and everything in that same line all the way to the throttle body. I actually took apart the valve that connects to the throttle body, it was plugged and easy to do. My line was clogged with charcoal tidbits not letting vacuum form which caused all codes to pop up. Next, take your throttle body apart (don't hesitate, it has no tiny components that might fall out and get lost.). Only thing I needed was a two leaf clover shaped gasket that I had to fabricate myself cause it tore. So preorder it. Clean it out well, your truck will thank you. After years of trial and error I finally have no acceleration rattle and btw, my charcoal canister is on its way, 50 bucks on ebay. It is from an altima but only difference I see is the mounting tabs. I did ALOT more to the truck but these were the actual solutions of my problems.