I recently noticed that at WOT around 3 or 4 gear my evo starts to sputter. Kinda of a jerking feeling. Im tuned for 25psi and since this started happening I can not get past 19psi. I searched and found others with the same problem but no explanation on how they managed to fix the problem. I've checked my ic piping and they are all intact. Ive also purchased new plugs, gapped at .25 but that hasnt managed to fix the problem. I dont know what else to do so if anyone knows of anything that could help please let me know.

 

sounds like some sort of ignition problem. try putting some dielectric grease on the boots

 

First- what heat range and what is the model number of the plug? Anything other than ILFR7H is incorrect.

Second- gap at 0.020"

 

Thanks I gotta get some tomorrow and give it a shot.

Those are the plugs Im using, heat range 7 stock for evo 9. Which come pre-gapped at .24-.25. Ive been using those for a while now without problems. I'll give .20 a shot tho thanks

 

do a boost leak test

 

closing the gap will fix the issue...look at getting a good COP setup!

 

maybe your coils are not in good condition

 

what ignition setup do you have?

This happened to my car when I had a coil on plug plate. I went with a different ignition system and solved the problem.

 

gap to 0.020 or 0.018 and do a boost leak test!!

 

The setup I currently have is a dual ignitor system, the sputter at WOT went away as soon as this was done to my car.

 

I had the same problem with same boost u r running all all...two things-1 my plug gap was too big and 2 I found two hair line cracks in my exhaust manifold which casued the car to sputter. Is check all that like everyone has states.

 

Thanks guys! I closed my gap to .20 and I also found a small tear on one of my ic couplers and it seemed to solve the problem. I now see the importance of a boost leak test, gonna go buy me a air compressor.