Okay so I’m new to this forum and the infinity family so I’m just looking to know a little more about my car and yours. So I have a 2004 infinity g35 coupe. Some quick info of the car it’s has 120k miles the motor is strong and seems well but it’s runs rough it’s feels really rich and doesint move how it’s supposed to. The previous owner is what we will call a “ricer” and did mods the non proper way, the air flow senors are cut by the front of the exhaust system and the car is straight piped, with a cold air intake. Im looking to make her stock and run good again and start from their. He said that their was a tune on the car & chip and I found no evidence of anything on the car. So the car runs crappy it makes no where near the power it should, it’s loud and not the good kinda loud it pops and backfires way to offend even when idling and it moves the same speed as my moms Honda from 97. I need some help and preyers. Sorry for the long story.

 

Take some pictures of the sensors that are cut off, the ones in the headers are actually the A/F sensors for the car and yeah it's going to run like trash (if it runs at all) when them disconnected.

 

I would start with ECU reset, new maf sensors and o2 sensors. Put cats back on.