steven88, wat year is ur tc or ur buddys? cause if its the 1st year if i remember u need to recalibrate ur ecu for the 02 code. i know u have a turbo kit on it but try that ... that is all the 411 i can give out at this time and yes and 02 code can make a car to misfire i have that 1st hand

 

it's a 2005 scion tc....i don't know if its the first year...could it be?

if the tC has to get the ecu recalibrated, how come turbonetics never said nuttin?

 

It should not need to be recalibrated. Turbonetics has very early model Scions from Scion North America and this never had to be done...

 

well i tried taking off the o2 sensor yesterday....theres no way i can get too it....too much piping and the engine cross member was in the way...i mean obviously i can take my time to remove everything, to gain access to it...but we already know its most likely the problem...so theres really no need to examine the sensor anyway...we tried connecting it back on yesterday and it ran like a$$ once again...

while i was down there, i took a look at his exhaust system....i'm not a scion tuner so i don't know how it looks like....but while i was down there, i saw this in order...

1. the exhaust manifold
2. turbo
3. downpipe
4. s-pipe (w/secondary o2 still connected)
5. catalytic converter
6. resonator
7. muffler

this sounds about right? damn his car is already damn fast even with the stock piping and cat still in place...i can just imagine if he went full 3 inch exhaust...or even open downpipe (removing the s-pipe)....easily 20whp gain i'd say

 

i had my s-pipe remove for a day while getting a bung welded on and man was it loud. Not worth the easy whp gain.

 

because this is only for ppl who are toyo techs. not all year will have this problem its just only some of 05 depending on vin or you could say that some mayb have this problem but it the sensor will wont go bad during a production date. im not disrespectin turbonetics or who sells the product cause myself im also intrested on the turbo kit too.

 

make sure your intercooler pipes are all attached well because i know the one on mine came undone that came off the throttle body and went down to the first intercooler pipe, which caused similar issues, but all runs well now weel for the past month actully and I have put 4k miles on it since

 

thanks for the tip...but i've made all the visual and audible inspections before moving onto further diagnosis....such as intake leaks, exhaust leaks...etc....besides, it's narrowed down to the o2 sensor for sure now...