Yeah, unlike a carbureted engine with an accelerator pump, these FI engines don't really have any way to counter the vacuum drop caused by punching the gas pedal. The move from throttle body injection to port injection helped reduce it, but did not eliminate it completely.

 

Have we ruled out the possibility of the OP's cat? That's what it sounds like to me.

 

i think the biggest problem is is that the keg is so damn big , thats why when we do the keg mod or the airgap we see such big gain in the low end

 

Is it really bogging...or just not moving out like you think it should? A "flat spot" or bog that is caused by a lean condition could or should produce a backfire. How did it run before the air cleaner was installed and how soon after did you notice the issue?

When I floor my truck from a dead stop it is hardly impressive. I attribute this to A. weight B. Low torque motor. C. Highway gears with big tires. D. Torque management in PCM. E. Huge vacum drop, low vacum signal under WOT. Any of these can cause your ride to feel sluggish especially from a dead stop.

 

I have a high flow magnaflow cat with a super 40 flowmaster. I'll be getting headers in sometime next week. But I agree with JasonW It's not really a "Bog Down" it just feels like when I floor it on the freeway I can hear it sucking air and the engine just acts a little weird. From a dead stop if I keep my foot on the brake and get the RPM's to about 2k and release the brake it's damn fast especially with my 4.11's now.

 

Of course it is. By doing that you've pretty much eliminated the vacuum drop that happens when going rapidly from idle to WOT because the butterflys are already partially open.

 

i had a ram air and it did the same thing on a stock tune it bogged down like crazy under anywhere near full throttle and i have a nice open exhaust so i think it might be too much air for the stock computer like he said up there ^^^^^^

 

weird, when i drop the hammer, my ol' truck just takes off like a bat outta hell :P

 

yeah mine just takes off, mabe you have a plenum leak