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2002 mpv code p0412

Old 07-24-2007, 06:24 PM
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Join Date: Jun 2007
Posts: 5
Default 2002 mpv code p0412

Just received this code need help locating and fixing this problem.
Old 07-25-2007, 07:30 PM
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Join Date: Jul 2005
Posts: 2,747
Default RE: 2002 mpv code p0412

P0412 is not used on the 2002 MPV. Could it have instead been a P0421?
That code would indicate that the right side warm-up catalytic converter located within the right bank exhaust manifold is getting weak and not cleaning the exhaust of pollutants as well as it should be.
Old 07-27-2007, 04:23 AM
Join Date: Oct 2005
Posts: 107
Default RE: 2002 mpv code p0412

A friend of mine got also this P0412 code in his 626 or Secondary Air Solenoid Circuit.. He mentioned that the mechanic saw an open or shorted condition detected in the secondary air (air switching/aspirator) solenoid control circuit and that some of his Mazda 626 performance parts are already worn out and needs to be replaced... But in case if it was a P0412, this code basically means that the oxygen sensor downstream of the catalytic converter on bank 1 is detecting that the converter is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system.You will likely not notice any drivability problems, although there may be symptoms. The code may be more likely to occur after the engine has had numerous cold starts in the past 1-2 days. Some cause of this code are malfunctioning catalytic converter, oxygen sensor or a fouled sparkplug...

The simplest thing to do is to reset the code and see if it comes back. Next step is to measure the voltage at the oxygen sensor on Bank 1 (the rear sensor, or the sensor after the converter). The voltage should be low and steady (~200mV, depends on the vehicle). If the voltage varies (e.g. 100mV to 600mV) then it's time to replace the catalytic converter. In fact, it would be a good idea to test each oxygen O2 sensor while you're at it. One thing to note is that many vehicle manufacturers offer a longer warranty on emissions-related parts. So if you have a newer car but it's out of it's bumper-to-bumper warranty, there still may be warranty on this type of problem. Many manufacturers give a five year, unlimited mileage warranty on these items. It's worth checking into. Good luck!!!

Old 07-31-2007, 05:10 PM
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Join Date: Jun 2007
Posts: 5
Default RE: 2002 mpv code p0412

Sorry for giving the wrong code that iw what the guy a autozone gave me. I reset the light and now it has gone off again. it is a p0421 please help me with this code.
Old 07-31-2007, 06:30 PM
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Join Date: Jul 2007
Location: Austin, Texas
Posts: 11
Default RE: 2002 mpv code p0412

this may help

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