This is my first post. I just got my first GP and it's got the 3100 in it.

It has a problem with bogging down a few minutes after driving. It gets 5 engine codes (P0135, P0141, P0131, P1133, P0300)

All of the codes come back to bank 1 sensor and misfires.

I have replaced the entire exhaust system, spark plugs, wires, and a general tune up.

My next step was checking for a vacuum leak, which unfortunately I've never done before. Any suggestions?

I appreciate any help or guidance. Thanks