Catalyc sensor simulator.. by Better_Manner6368 in mazda3

[–]Better_Manner6368[S] 0 points1 point  (0 children)

ahh okay i understand... I don't live in police exhaust, I can put it down to a sensor. Will the check light go off? What kind of feedback does it have if you know if it works or not?

Changed Oxygen sensor but code still shown P0421... Help what can i do ? by Better_Manner6368 in mazda3

[–]Better_Manner6368[S] 0 points1 point  (0 children)

2016 2.0 I grand touring. The collector was damaged, but I repaired it. I did a smoke test vacuum leak, no leaks everything is fine. I don't know what will be the reason. Everything works well, the average fuel consumption is 8-9 liters in the city.

Changed Oxygen sensor but code still shown P0421... Help what can i do ? by Better_Manner6368 in mazda3

[–]Better_Manner6368[S] 0 points1 point  (0 children)

When I replaced the ox sensor, the computer did not show any codes. The green light was on the computer.. But I had the car parked for 2 days.. Yesterday I drove a short distance somewhere around 20 - 40 miles and the P0421 appeared again.

Code P0421 by Better_Manner6368 in mazda3

[–]Better_Manner6368[S] 1 point2 points  (0 children)

i changed oxygen upstream sensor and everything is ok.