You have a coil going bad. It is probably dropping a cylinder under load. Mellon helped me find a similar problem earlier this year.
Just replace one coil at a time with "a known good sample" and you'll find it.

Darin

 

check the throttle body for carbon build up, check the maf to make sure it's not oiled up. Compression test and try and swap coilpack with another evo owner.

 

I suggested earlier when I was on the phone with him that he swap the coils/wires out with someone else after he reconnects his piping if the issue remains. It's going to be something silly like that...always is.

 

i completely forgot my borthers car is in town being stored so im awaiting his permission to steal his coils to test. i should know if its coil related in the next day or 2.

my buddy thinks my bov is bad so im going to change that out with his just to rule that out

 

perfect, I'm sure you'll figure it out soon

 

my buddy had the same problem for the longest time we just replaced the plug wires. the car sputtered so bad like a machine gun misfire. the tuner did not evern know what was wrong with the car i am the one that suggested replacing the wires and it worked. try that hopefuly you have a buddy that has a evo and you guys can swap them just to see if it works.

 

I talked to Zane this afternoon, the next test will be with a friends coil/wires and if that fixes the issue he's talking about getting a coil on plug setup.

 

Couldnt this sound also come from a damaged filter if its squeezed to hard? I have an HKS intake that started happening. I just realized when i took it off the other day when applyin the load on an EBC(EVC5). The wastegate max would read only 89-93Kpa(10-13psi) and not 103-105Kpa(~15psi). If this doesnt resolve would a filter swap, could it be my plugs? Im only tuned for 26psi w/ meth @ CBRD. Evo9 SE with only 24K would need new plugs so soon? If so whats the best choice and gap size?

 

evo 9 plugs suck, i say colder plugs, or like everyone the coil might be going ou, or spark plug wires

 

ive changed the plugs to a 1 step colder and changed bov and it still does it. looking at the coils-wires now trying to find a donor car. will evo 8 coils fit on evo 9?

 

filter, whay brand/model spark plug did you use? for some reason, my evo has got an NGK IGR7A-G... i dont know if this is what it came with stock from factory.

 

yes evo 8 wires fit i know because that is what the shop used on my friends car

 

03 evo 8 stock turbo stock boost, CIA, AGP intercooler, and Apexi catback exhaust
I have the same issue with my car, After 4500rpm 16-18psi it spudders like mad in any gear and only at WOT. I have the iridium bpr7eix spark plugs with about 7,000 miles on them. I also have the Magnacore wires on my car too.

I have done boost leak test - no leak
I have checked compression it goes 180, 179, 179, 176 left to right
Spark plugs are a light grey color with some carbon build up around the outer ring
Im going to look up how to test a coil packs here and see what happends then
And im going to switch back to the old wires to see if that helps!

 

try the stock wires, not sure why everyone is so quick to "upgrade", the stock wires are good.

 

@filter
did u fixed ur problem ?
if yes plz tell wat u have done so that ill do the same