My first (and last I hope !) backfire

[plissken97]

Hi guys,

I'm Julien, I live in France and I owned for 4 years now a beautiful black 1990 ZR-1.

I made this backfire last friday...
My SES light came on.
I got 3 fault codes after my diagnosis : H33 H45 H65.
I solved 2 codes which were the H33 and H65 by putting in place the MAP sensor hose at the back of the plenum.

Unfortunately, it remains my SES light with a H45 code.
It says "Oxygen Sensor (System Rich)".

Can you help me to solve this issue ?

Thanks a lot.

Julien