hi to all
I've a 2005 scion TC that i bought in oktober last year and I've made some modifications to it DC 4-1 headers and a Typhoon cold air intake but since then the CEL has turned on and give me the code 0420 that indicates catalist efficiency below threshold then I've decided to buy an O2 simulator at miami speedshop where i've bought the headers and the cold air intake but it did not turn off the CEL and the number of codes has increased because i got a new code 0137 which indicates the O2 sensor circuit low voltage(bank 1 sensor 2) too
can anybody help me with this problem?
thanks in advance

 

not trying to sound negative but if it hasn't worked for you yet then it wont. I had the same issues. To correct this weld a o2 bung behind the cat on the midpipe assume the midpipe is stock hopefully it is for your sake and cel. And relocate the second o2 sensor from the s-pipe to this new o2 bung.

 

02 sim will damage your ECU programming, isn't 100% and might now pass you in smog. A better way is to use a spark plug defouler.

 

The spark plug antifouler didn't work for me. I had tried about 20 diffrent combinations with it. I have a laptop and can datalog live engine data from every sensor and nothing works except my o2 bung after the cat and relocating the sensor.