P0420 and P0325

[blkblkblk04MDX]

Hi guys,

We've got an 04 MDX with the check engine and the VTM4 light on. Its right at 100,000 miles.

The codes are:
P0420 and P0325

Does anyone know of a typical part that dies when these codes are on or at that mileage?

Any help is GREATLY appreciated, as Acura wanted 95$ just to diagnose it!

Thanks,
Sean

[midnightMDX]

P0420 seems to refer to either a bad cat or O2 sensor in cat.

P0325 is the knock sensor.

[blkblkblk04MDX]

Cool thanks midnight. Is there a way I can check any of this without taking it to the stealership? I've got a voltmeter and clamp on amp-meter, not sure if its reasonable to try to clip on to any part on the sensor and take a reading...

I'm not above stripping a little bit of a wire to take a reading if it will help identify the problem beyond a shadow of a doubt (and of course if the sensor is okay just dab some liquid electrical tape to cover the exposed wire)

Are you an acura tech by chance?

would/could the misfire code be because of the bad O2/Cat?

Thanks again,
Sean

[dtrinh]

I got a 04 MDX with the same P0420 code but not the other. Mine was a cat and the part cost something like $350 from the dealer.

[winr602]

My wife just bought a 2001 MDX knowing that it has a transmission problem. I took it in a local tranny shop and had them rebuild it ($2950 out the door). After the tranny was fixed, the shop called and told me that it's throwing a P0325 and a VTM-4 error. So, I called my Honda/Acura mechanic and had him replaced the Knock Sensor and the single wiring harness ($50.00 parts and $175.00 labor). The Knock sensor was cracked. The single wiring harness was also replaced because it came off from the Knock sensor. Also, I'm hoping that rodents doesn't start chewing on the harness.

[mdxer12345]

anyone got the dealership to cover the 420 cat converter code? is there a mileage limit? i have an 03 mdx. for some reason it was on... .and while driving turned off.

would seafoaming your intake mess up your cat convertor? i have heard that people have sprayed sea foam into their intake to clean out deposits and it created a lot of smoke.

[edmmdx]

Originally Posted by winr602

My wife just bought a 2001 MDX knowing that it has a transmission problem. I took it in a local tranny shop and had them rebuild it ($2950 out the door). After the tranny was fixed, the shop called and told me that it's throwing a P0325 and a VTM-4 error. So, I called my Honda/Acura mechanic and had him replaced the Knock Sensor and the single wiring harness ($50.00 parts and $175.00 labor). The Knock sensor was cracked. The single wiring harness was also replaced because it came off from the Knock sensor. Also, I'm hoping that rodents doesn't start chewing on the harness.

Does any one know if the Knock sensor "cracking" is a common problems with the first gen X. I recently have mine replaced, and the mechanic said the sensor was cracked. He also said it was odd that it cracked because nothing can come into contact with the sensor.