Hello, i'm new to the site but I've been reading alot of threads and I can not find the answer to my problem. I recently bought a 2002 Subaru Wrx. It was dyno'd at 245whp and 240lbs of torque. The car has some modifications to it. Here is a list of them:
2002 Subaru WRX
124,XXX Miles on Chassis
39,XXX Miles on Motor and Driveline (Motor replaced by Subaru w/ Paperwork)
**Oil Changed every 3,500 Miles with Shell Rotella T6 5W-40 and Bosch 3310 Premium Filter**
MODS:
Engine-
New Shortblock from Subaru replaced at 85,XXX miles
COBB Accessport- Will be included in sale
Full Invidia Turbo Back Exhaust
All Exhaust Gaskets are Grimmspeed 3x Thick Gaskets
Perrin 2.4" Turbo Inlet
Deatschwerks DW200 Fuel Pump
NGK 1 Step Colder Iridium Spark Plugs-Just Replaced
STi TMIC
STi Bypass Valve
HPS Intercooler Couplers
Extreme Turbo System-Couplers
Cobb Short-Ram Air Intake
Cobb Short-Ram Air Box
CX Racing Radiator
GrimmSpeed EBCS
GrimmSpeed Catless Up Pipe
ATI Triple Gauge Pod
SMY Gauge Delete Cap
AEM UEGO Air/Fuel Ratio Gauge
STRI Boost Gauge
Protuned on Mustang Dyno by STi Mikey 245/240
AFR set to 10.9 at WOT and 14.4 at Idle
Killer B Alternator Shroud
Exterior/Interior/Suspension/Driveline-
Full 07 WRX Driveline: 07 WRX Transmission, Center and Rear Diff, 07 WRX 4-POT 2-POT Brakes, 07 WRX axles, 07 WRX hubs- Castrol 75W-90 Transmission Fluid
Hawk HP Race Pads- Tend to Squeak because they are heavy duty
Dorman Wheel Locks
Stoptech Cryo-Treated Rotors
Tein S-Tech Springs
TIC Rear End Kit: Rear Differential Bushings, Rear Outrigger Bushings
Kartboy Short Shift Kit: Short Shifter and Front and Rear shifter stay Bushings
Blox NeoChrome Shift Knob
XXR 518 Wheels
FastWRX Wheel hub adapter kit
BFGoodrich Sport Comp 2-
Painted WRX Side-skirts
WRX OEM Front Lip Kit
Wingless Trunk
JDM STI Projector Headlights
Hella Supertone Horns in Red
WRX Front Plate Delete
30% Tint On all Windows Except Windshield
That was the list. My car pushes 19lbs of boost. Now, heres my problem.
When the car hits around 15lbs of boost and still going up, the car kind of jerks excessively and it doesnt sound good. I was thinking it is either the spark plugs or i need bigger fuel injectors. I don't know if any of the modifications is doing it. I don't know what is doing it. Can someone tell me how to fix it?