no no boost cut the car is tuned for 25 with a spike to 28 it still happens at 17psi just doesnt shutter as hard . it feels very similar to an ic pipe blown off but they are all on tight. and there are no codes thrown. im thinking this is the fuel pump and not a spark plug because my milage is still the same as it usually is. could this be? in other words the walbro isnt swithing to 14v like its supposed to?

 

Get a wideband on there and find out.

 

got one comn in the mail already

 

You could have possibly reuptured one of the vaccum lines also. My car was doing this fluttering thing once I got above 15 psi and come to find out I had ruptured my vaccum line right at the BCS... and or MBC

 

Those are not the right plugs for an Evo IX, that is a VIII plug. The Evo IX has a long reach plug (26.5mm), you need either the OEM NGK-ILFR7H or the Denso IKH22. The IKH24 is an affordable 1 step colder plug for the IX's, the NGK's 1 step colder are uber expensive. I only recommend the NGK or Denso plugs.

http://www.sparkplugs.com/results_ap...1&AAIA=1432585

 

yea get the denso ikh24. just bough my second set,, on ebay for $38 shipped.

 

ok i beleive it was plug number 2 as it was the most fould plug of the bunch and now its running awsome again thanks for the help guys