Hummer H3 o2 oxygen sensor p0420 Catalyst System Efficiency Below Threshold (Bank 1)

[@alanhernandez9552]

Just an FYI I just spent about 300 dollars trying to fix this code... What was going on is the wire that heats the O2 sensor to normal operating temp wasn't working. So after literally replacing everything including O2 sensors and catalytic converter/headers... I found out the O2 sensor connector was bad. It was burnt and some wire was showing but I never saw it since it was more inside of the connector from the engine harness.

[@sheltonberryjr]

Where can you find that wiring harness

[@elpalenquedeoro]

Any gm vehicle are known to have ad wiring harnesses its ery important to do a correct diagnosis on everything on these vehicles

[@sapphirejan2040]

He made that look so easy and so simple.

[@Zen2Motion]

Great Video! Thanks

[@chia-weihsu7303]

Does the code come back after a while? I have a two year old catalytic converter and now I have the same code as you. I also consider to change the O2 sensor first because I guess the O2 sensor is not working properly (o2 sensor is also two year old now).

[@puy389]

well theres your problem your steering wheels on the wrong side!

[@Alex-vu5uu]

I changed the one that is in the trunk... But I still have the problem after the reset on the computer (it went on again after 10 miles)... Any ideas?

[@DrFahdMirza]

Legend

[@alidoubairo4504]

i have oxygen sensor light and cam shave sensor and krank shave sensor and selenoid in gear box

[@davidavalosamaya6573]

Did you fix it??? And how??

[@-IljaajlI-]

то что нужно!!!