zentech

Mazda 3 2013 2.0L
My car engine has a tacking noise, it doesn't sound really bad, you really have to pay attention to hear it. sometimes you can feel the engine vibrating a bit, especially when the AC compressor kicks in. But also happens when AC is off. I hooked up the scanner and I got P0172 error "System Too Rich" that usually means the O2 sensor is detecting more fuel than normal on the mix. It suggest to replace MAF. I checked MAF and seems to be working just fine. I cleaned it, also cleaned the Throttle body, but still doing it. Any suggesting where to look next? I'm posting a link to a video that sound very similar