1eltaino

Hello everyone..i recently bought a 02 gs300 and the next day me check engine light came on.I took it to my mechanic and he said i needed a new cat..the code that came out was something about low threshold..i went and bought a aftermarket manilfold converter from rockauto walker brand and the mechanic installed and reset cel but came back on,he said all the o2 sensors are good but its hard to believe,not sure what would be my next step can somone please help

kevin3344

Be careful how you interpret those OBDII codes. While driving on the freeway last summer I got a P0715 - Turbine/Input shaft speed sensor circuit and my car wouldn't go into manual mode...I thought my transmission was going out. Turns out it was a bad fuel pump (dealer did a pressure test and has been fine since).

At the same time, I also got a P0430 code - Catalyst System Efficiency Below Threshold (Bank 2) and thought it was my catalytic converter, turned out it was my Y-pipe. Dealer replace that and all is well.

Yes, the dealer is more expensive but it beats replacing parts you think might be the issue.

Mcon

iTrader: (1)

[QUOTE=kevin3344

At the same time, I also got a P0430 code - Catalyst System Efficiency Below Threshold (Bank 2) and thought it was my catalytic converter, turned out it was my Y-pipe. Dealer replace that and all is well.

Yes, the dealer is more expensive but it beats replacing parts you think might be the issue.[/QUOTE]
This is the Y pipe
When I take it out, this is what come out. I go to the muffler show and cut it and add it a small pipe.


100% agree with you. Check your Y pipe. On the Y pipe you have a extra catalytic. Mine was clogged. This was my Y pipe.

1eltaino

I am new to this forum but i am glad that you guys could help i definitely appreciate it and will look into that y pipe