Question about 2004 Mazda 3
Here's a link to your code. Trouble Code P0420 Catalyst System Efficiency Below Threshold Bank 1 IF YOUR OIL NEEDS CHANGING, TAKE TO DEALER AND LET THEM CHANGE,THEY WILL FIND PROBLEM CODE AND TELL YOU WHAT'S WRONG AND HOW MUCH TO FIX,THEN IF YOU THINK YOU CAN DO IT,THEN YOU WILL FIND OUT WHAT'S WRONG FOR FREE AND NOT REPLACE PARTS TO SEE IF THAT'S IT,THIS IS WHAT I DO WITH MY TOYOTA THERE SCAN TOOL PIN POINTS THE PROBLEM.
Posted on Apr 02, 2014
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Posted on Jan 02, 2017
SOURCE: Mazda mpv O2 sensor wires?
Put some penetrating oil on them and let it soak overnight. This will break up the rust and other build up. Make sure that it is penetrating oil, you can get it at any automotive store.
Posted on Jun 28, 2008
SOURCE: O2 sensor
There should be two O2 sensors. If you look inbetween the engine and radiator following the exhaust manifold down to the exhaust pipe you should run into the 1st O2 sensor, following the pipe down stream under the vehical towards the catalytic converter you should find the second O2 sensor. The 1st O2 should be easy but the 2nd might be difficult depending on your abilities. Coils will depend on 4 or 6 cyls, 1 for each cyl. Repair man, go to, pep boys, napa, auto zone, advanced auto parts to name a few.
Posted on Mar 18, 2009
This code does not always mean the O2 sensor is low, but if u want to replace it here is the info to do that and the part number.
The sensor you want is the one in the exhaust pipe of the engine cylinder bank that has #1 cylinder in it, as you face the engine with the hood open the cylinder bank u want is the rear bank, u will need to jack the car up and get under it to remove the sensor, u may also need a special socket to remove it, the sensor is the one that is before the catalytic converter. part number is:DENSO Part # 2344068
REAR; Before Catalyst
Posted on May 20, 2009
See page two on this PDF file HERE
Posted on Mar 06, 2010
SOURCE: I have my check engine
bank 2 is the bank that doesn`t have cylinder #1 in it.sensor 2 is the sensor after the catalytic or at the rear of the catalytic converter.with mazda use a good quality sensor(preferedly factory) as if its poor quality sensor it will set a code and cause problems.you also usually have to cut and splice the wires to the original plug to use them.try buying one from a parts store that you don`t have to cut and splice that way it theres a problem with the sensor you can get it replaced easier.
Posted on Apr 27, 2011
Testimonial: "awesome, but still a bit confused.lol. thanx and sorry.lol."
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