Misfire on number four cylinder and lean bank on, codes P1404, P0270, P0304 and P0030

Hi,

Let me layout these DTCs first.

P0030 - Bank 1 Sensor 1 o2 sensor malfunction
P0270 - Cylinder 4 injector circuit malfunction
P0304 - Cylinder 4 misfire
P1404 - Leak detection pump circuit malfunction

Start with the P0270 code and go through that testing. I suspect that is the cause of the others so if we fix that issue then we will fix the others.

Are you familiar with how to test for open circuits and shorts?

Here is a guide that goes through the basics:

https://www.2carpros.com/articles/how-to-check-wiring

Please let me know what you find or if you run into issues and we can walk through this but unfortunately I suspect you have a wiring issue so we need to go through this testing. Thanks

You are welcome. Please let me know what happens. I will wait to hear back. Thanks