ap-evo83

iTrader: (3)

had these installed in my car

RNR GT35r with equal length manifold
hallman mbc @20psi
RNR intercooler
RNR TBE with HF cat
hks 272 in/ex
arp headstuds
walbro fuel pump
s afc2
dynoflash

had these installed last week and i noticed that during WOT on fifth gear the car would hesitate or stumble. boost wont go beyond 15 psi's, but sometimes it would. after a day or two, while driving on the freeway-SES light turned on.stock bov flutters alot so i ordered the jdm mr bov. installed it today-no change.
i let the car cool down. went on the forums to search for answers. had ideas so i drove the car again after 3 hours.No hesitancy-car was pulling great. but after 20-30 minutes the stumbling/shaking starts again. i have the stock spark plugs which i will install tomorrow.and i will buy new spark plug wires.
Any input will be highly appreciated.

ap-evo83

iTrader: (3)

bump

GTVEVO

iTrader: (22)

Man this could be several things but I recommend that you get a datalogger or ODB2 reader on it so you can look at all of the vital signs when this happens. I would do this before driving your car hard again.

Do you notice anything funny going on with your maf signal on your AFC when it happens?

RnR Racing

iTrader: (23)

When you bring it down on Wed we will take a look at it. It is probably something simple giving you problems.

thebluesky

iTrader: (28)

just out of curiousity, when did you have the dynoflash done? before or after the new mods?

ap-evo83

iTrader: (3)

before the mods. P0420-just got home from autozone

ap-evo83

iTrader: (3)

thanks ryan

steveevo8

what exactly does that code mean?

ap-evo83

iTrader: (3)

"The PCM has determined that the catalyst system effeciency for bank 1 is below threshold for the current engine operating conditions.

03EvoVIII

iTrader: (4)

Sounds like your front o2 sensor....

jj_008

iTrader: (8)

P0420 can be thrown if you have a HF cat or test pipe.

steveevo8

see i think i am throwing that code as well once i put my catless tbe exhaust on i have had this problem, i'm gonna give that mechanical 02 fix a try on friday and see how that works out.... i'll let you know if it works or not man

ap-evo83

iTrader: (3)

i will try it too. but the one that bugs me the most is the hesitancy/stumbling when i have been driving for a long time.

ap-evo83

iTrader: (3)

anybody else have an idea on what csuses the stumbling?

Ev0 1

iTrader: (1)

Did you fix it? I think its the spark plugs..