Problem with my B3000 V6

[Cordel101]

I have 03 Mazda B3000 with the 3.0 in it. I have a really rough idle and a check engine light that come on after the 200 mile of clearing the light. Check engine lights reads- missfire on cylinder 3 and bank 1 system to rich, and miss fires on start up. I have just had both head rebuilt because the seats where bad, which didn't help the rough the idle and I have changed the plugs and wires and I even tried a new coil pack but it didn't help either. Vacumu line have been checked and all are good. If any one have any other ideas that would be great.

 

[2stroke]

So is that KOEO test? The three things I would look at are a dirty MAF, exhaust leak, and a bad upstream bank 1 O2 sensor. Cleaning the MAF is easy, and you can hear an exhaust leak. Look up how to diagnose a bad O2 sensor with a code reader.