1eltaino

Ok so ive been going through this big headache. I bought my 02 gs300 about a year ago and the next day i bought the car my cel came on for catalyst efficiency below threshold.I never used the scanner myself i always had a mechanic plug it in.I had two mechanics say i needed a cat,and that the o2 sensors are good..so i ended up doing a couple things to my car before i put the manifold converter on.I did the timing belt,water pump kit,spark plug and wires ,ignition coils,valve cover gasket etc..then i bought the manifold converter ..long story short after it was installed the cel was reset and came back on 5min later.I eventually installed the rear cat and resonator cause i had a leak where the rear cat joins with the manifold converter and also it was rusty down there,anyways the bottom is all new basically with all new gaskets anf now i still have the cel on.I went to autozone yesterday and haf them check for me and me see with my own eyes what the codes are..so i got these codes and it still telling me catalyst efficiency below threshold..Im hoping if i change bank 1 sensor 2 this cel will go away..if someone out there can please help me and give me some input i will appreciate it.Thank you

Debonair

Post the actual Diagnostic Trouble Code (P####) you have on your car.

1eltaino

1eltaino

And the p0430 code but i have replaced with all new cat

Debonair

P0141 is for Bank 1, Sensor 2. There are 29 threads about P0141 in the 2GS forum that can be found by searching "P0141".They all seem to point to the B1S2 sensor and exhaust gaskets. You can find the Bank 1 Sensor 2 location HERE.

1eltaino

Thank you for your help.The pics and guide should help me alot.I appreciate it