P0420

[x99suplarax]

i got the code P0420 bank 1

P0420 – Catalyst System Efficiency Below Threshold (V-6 engine)
· Three-way catalytic converter malfunction
· Open or short in heated oxygen sensor circuit
· Heated oxygen sensor malfunction

i dont have a cat on my car.. could that be the problem? or could it just be the o2 sensor?

also, is this an immediate fix or can be drivable for xxx amount of miles?

[1gSE]

How long have you been catless? IIRC, that o2 sensors job is basically to make sure the cat is working and doesn't really affect the a/f ratio (someone correct me if im wrong) You can try the anti-fouler mod

[x99suplarax]

About 8 months to year ago when i put obx and drift spec Muffler.. but changed o2 and knock sensors about 4 to 5 months ago..

[Midias]

yea it is because you don't have a cat. Get some anti foulers or an O2 sim.