I cut off half of that diffuser, and my gas mileage hasn't gone up or down. My throttle response is sooo much better. It took me a little bit to get used to not having to mash the gas to get anywhere. Its sensitive, but not jumpy. I recommend cutting off half the diffuser instead of all of it, at least to start. I heard that people who cut off all of it started running lean inthe front (?) Cylinders. I could be wrong. With half my diffuser gone, I have had absolutely no problems.

 

Old thread bump...

I did this last night. feels much better, maybe a couple jumpy spots in the powerband, but all around a better feel in the pedal

as per mpg. i have no clue, and really wont know until summer. i would say to a good driver, that can manipulate the pedal right, you can get more speed with less pedal so mpgs should go up. how much? who knows

 

The difference was very noticeable on my 5spd truck. Trust me, I was skeptical at first, but under 2000rpm the truck feels a lot better. Feels a lot stronger at 1500rpm which on a 5spd is key to having a nice cruise.

 

did this to my blazer before i even found out about this site instead of cutting it though took the blade off and filled the 2 holes left with screws and 2 bolts each and totally destroyed the thread on hasn't come off since hell i beat a 03 mitsubishi spider in a take off

 

On my old blazer i did this. I just used needle nose pliers and bent it back n forth till it broke off. Then filed it down. I was worried about the front plugs fouling/burning out, so on my 05 I have now, I just placed two notches on each side half way up. This improves throttle response and still has some baffle left to not allow to much air to the front plugs. By the way you can go to your local junkyard and get as many as you want off these. I have three on my bench now.

 

I did mine with no problem, I think you will only get bad mpg when you floor it. I like having that extra power when I need it.

 

Just did mine, took about 15 minutes. No cel lights. Does seem to get up in the rpms faster, but only one test drive. Maybe just, NMS, new mod syndrome

 

After more driving I`m happy with it. Seems like I`m not dragging something or the brakes are hung up on take off. So it seems worth it

 

I did this, pretty easy to do. Throttle is definitely more sensitive, probably didn't gain any horsepower from it though.

I ported the airbox while I was at it. Not sure it makes a difference on the 4.3, but it was good for about 3-4 rwhp on my 2000 4runner with the 3.4.

 

After I resolve my "jerking" issues, I'm definitely giving this ago. Probably wouldn't be a good idea till fixed, huh?