im having issues with my car sputtutring bad on high boost. my 2nd gear is set up to 14psi car runs fins. then when i throw it into 3rd my boost is set up at 24 psi thats when the car starts sputtering bad. same goes with my 4th. 1st and second are fine. the only thing i did to the car was change my FPR i had and got tuned using an AEM with a base fuel pressure of 45psi. i swapped my rail and also installed an aeromotive i had laying around...would the 1:1 lb of pressure per lb of boost affect/ throw off my high boost tuning. im running ngk 8s gapped at .15

 

Sound like a retune session is in order

 

yup thats what its started to come down too.

 

Do you have a wideband in the car? I would think that either datalogging an accurate AFR or having a wideband in the car at that much boost would be a necessity. Sounds like an AFR problem, or could be time for a new coil/igniter/plugs or wires. But changing something like the rail and regulator from stock to aftermarket are going to require a retune.

 

well beign that im fairly new to the whole s300 system i havent really figuered out the whole datalogging thing.

 

would running c16 cause my o2 from my wideband to not read correctly? cuz after i started running the racefuel my widebamd just stays at like 14.2 reguardless of how im driving it