I'm pretty sure this is issued because the car is running rich and I have a check engine light to  how can i find one 

Read your codes from the ECU. Decipher them from the list. Go from there. 

Sounds to me more like one of the following: 
- bad or dirty AFM 
- dead O2 sensor 
- bad/dead coolant temp sensor 

Don’t go throwing money at it until you know what the codes are

Cheers 

Bennie

My lazy method would be to renew O2 sensor first, or more effort would be to decipher which incoming wire at ECU is O2 sensor and measure it's input from cold start to warm and throttle blips. Poor condition injectors if you have mpfi or I bet you have spfi ??

 

First step would be to disconnect O2 sensor and see what difference you get and share result of the most simplest diagnostic step

 

Edited September 3, 20223 yr by Steptoe's photos