Active exhaust issues

I don't know about the active exhaust thing, don't know why it would have changed its behavior a little while after the install, assuming it was working normal after the install

regarding the tune -- it is probably running a bit lean, should be OK as long as you go easy, no heavy throttle and no lugging the engine until the tune is installed

Braindead said:

... lean condition regarding CAI. If so it appears those really work- more air? ...

Click to expand...

Minor tangent: the reason it is likely running a bit lean, is not because it is flowing more air. It is because the MAF (Mass Air Flow) readings going to the computer are wrong. Most aftermarket intakes have a bigger tube than stock, and this throws off the math that the computer does with the signals coming from the MAF sensor. The MAF sensor basically measures velocity (of the air) and then (oversimplifying) multiplies velocity by area of the tube to get volume (and mass) of air coming in; then it commands the right amount of fuel for that amount of air. If the tube is bigger than the computer thinks it is, then it is calculating less air than is really coming in, so it commands less fuel than is needed, and it runs lean. The "tune" corrects this math.

yep, if you go to a bigger tube but have the exact same air coming in, the velocity will be lower, the computer will think there is less air coming in, it will command fuel for that lesser amount of air, and it will run lean .... then I think the O2 sensors will detect the lean condition, and attempt to compensate (not sure if that is what you mean by "compensation") ... but it can only compensate so much, plus I think it detects that something is off in the math, and that's what triggers the CEL

about the TB spacer -- my guess is they realized it didn't do anything at some point, and decided not to bother putting them in ... or they ran short of inventory