2017 Cub Cadet challenger 750 runs rich

[motofan91]

Recently acquired a 2017 Challenger 750. Previous owner ran it low on oil so I had to do a top end. Starts and runs but it seems to be running very rich. There isn't too much information available for troubleshooting the EFI system. Air filter is new and I even tried running with it removed with no change. Some of the parts are relatively cheap, so I did replace the IAC and the MAF sensor. Could this be related to the TPS sensor or which direction should I head in next? There doesn't seem to be any adjustment on the TPS and I have read something about a WOT ECU reset but that didn't change anything. 

Thanks in advance

 

[BOB PAOLINI]

Is it running rich because you smell fumes in the cab?

 

[gcrisler]

Check the 02 sensor connector. It has 4 pins and one of the pins on my unit was complete rotted away. Cut out both connectors, spliced wires together.