Strang problem w/ foot off gas...IAC?

[vertigasen]

**EDIT** Well crap, apparently I can't type when I write STRANGE....

Ok, this problem just started over the last 2 weeks or so, but getting worse every day.

I'm driving along and remove my foot from the gas pedal. It is fine for a second then, a nasty droning sound. It is almost like an automatic that downshifted. Also, at the same time, my wideband goes to 30 then to the infinity symbol. I barely tap the gas...and it is back to normal, again, for only a second then back to what it was doing before. I drove on the interstate yesterday and it was horrid. If I got behind someone driving slow in the fast lane, right after I would let off the gas, @ 70 in 5th, the droning sound would start, the wideband would go off the charts.

Would the IAC cause this? I cleaned it when I did the KB install less than a year ago, but it still has about 93k miles on it. I know I need a new DPFE sensor since I put a small crack in it, but I sealed the crack. I am just trying to narrow this down because it is starting to tick me off.

Thx for the help

 

[midnightdriver]

**EDIT** Well crap, apparently I can't type when I write STRANGE....

Ok, this problem just started over the last 2 weeks or so, but getting worse every day.

I'm driving along and remove my foot from the gas pedal. It is fine for a second then, a nasty droning sound. It is almost like an automatic that downshifted. Also, at the same time, my wideband goes to 30 then to the infinity symbol. I barely tap the gas...and it is back to normal, again, for only a second then back to what it was doing before. I drove on the interstate yesterday and it was horrid. If I got behind someone driving slow in the fast lane, right after I would let off the gas, @ 70 in 5th, the droning sound would start, the wideband would go off the charts.

Would the IAC cause this? I cleaned it when I did the KB install less than a year ago, but it still has about 93k miles on it. I know I need a new DPFE sensor since I put a small crack in it, but I sealed the crack. I am just trying to narrow this down because it is starting to tick me off.

Thx for the help

Well from what I have heard and from my own experience it sounds like your injectors are shutting off to conserve fuel. The sound you are hearing is the engine braking (Ie, the use of compression to slow the engine down). When the computer senses no throttle input and your engine is spinning more then idle rpm and is maintaining that rpm (or not dropping like a rock). Then the computer shuts the injectors off because you don't need them at the moment, but when you tab the gas and send a throttle input single the injectors re-fire making the noise go away until you let off again.

The wideband does not register or goes off the charts, lean I am guessing because there is no fuel burning in the combustion chambers (injectors not firing)

If you just installed the X pipe and gutted you cats, then the X pipe is breaking in and that is why the noise is getting louder.

If this is not a new X pipe, I would say your tune is out of wack or something computer related.

 

[vertigasen]

Had my x-pipe for about 5 years, so that isnt it.....

I have also had this tune for over a year.....

Anything else I should look at?