2004 to 2020 Mazda 3 Forum and Mazdaspeed 3 Forums banner

1 - 2 of 2 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1 (Edited)
Dear Members,
I have recently had the MIL activate, I scanned the Power Train Module and the code P2251:FF come to screen,
I replaced the Upstream O2 Sensor as I read that its gone faulty, with and exact same one [same part #] from a wrecker
and now P0134:FF has come come to screen,
Should I have replaced the down stream one also from the same car I removed the upstreem one from ?
I have read to check the connectors, wiring, and O2 Heater fuse,
where the connectors and wiring is ok
going by fuse box diagrams on the Web, the fuse is under the hood in the fuse box,
but alas, there isn't any fuse on this model for the O2 Heater, in this Australian BK Model ,
So I am at loss how to fix it, with out starting the pull the car apart.
any suggestions are most welcome.
TIA
 

·
Registered
Joined
·
4 Posts
Discussion Starter #2 (Edited)
Update,
After I did a bit more reading and research, I found that the Sensor on the Exhaust manifold was NOT the O2 Sensor,
its the Exhaust Manifold Air and Fuel Mixture Sensor, [but AKA as a O2 Sensor, where they call that the Upstream Sensor]
Where the one further down just under the fire wall is also called the Upstream O2 Sensor, because it doesn't seem to be a CAT between the lower to O2 Sensor.
So I went back the the wreckers and got the upstream O2 sensor [Pre Cat] and replaced the original one that was in it.
I did notice it does not have a Post Cat Sensor. [for what I could see while laying under the car.
After resetting the DTC, the Car drove great for about 3 road tests [approx. 30km/s],
but when I had let it sit for a couple of hours,
I started it up again, the MIL was activated again with the same P0134:FF DTC.
So both Sensors came from the same car,
So its got me stumped,
On the weekend, I will check the exhaust manifold to make sure its no leaking,
And the Wiring, where nothing has changed in the wiring area.
 
1 - 2 of 2 Posts
Top