Polaris 700-800 EFI Platform ATV's & sidexsides use a Bosch T-Bap sensor to calculate fuel adjustments. This fuel injection system is a pressure and temperature compensated alpha-N system. This EFI system uses RPM and throttle position as well as air temperature and barometric pressure to calculate an amount of fuel to deliver to the engine. When the T-Bap sensor is not working the ECU defaults to using only RPM and throttle position to calculate the amount of fuel to deliver to the engine. When this default condition occurs when the sensor is unavailable there is no temperature or pressure compensation, so when you ride the ATV or sidexside at different elevations and air temperatures the fuel air mixture going into the engine is going to be wrong. The Bosch Temperature/Barometric pressure sensor is a very good sensor and rarely fails. Usually what fails is the wiring connecting the sensor to the ECU. Here are some details to help you figure out if your wiring on your air temp/barometric pressure sensor is bad. Symptoms of broken Temp/Baro sensor wires: 1. The ATV will run very erratic at idle. 2. The "CHECK ENGINE" will sometimes come on. 3. Diagnostic codes 41 and or 45 will be present. 4. Fuel mileage will be poor. 5. Exhaust will smell really rich. Sometimes even black smoke can be seen from it running so rich. How to test if the Temp/Baro sensor wiring is broken: 1. Turn the key switch on and off 3 times leaving it on the 3rd time. This puts the ECU into diagnostic mode. If codes are present their numbers will be displayed on the instrument cluster. When all codes have been displayed "End" will appear on the cluster. 2. Remove the seat and locate the sensor on the air intake tube. Unplug the wiring to the sensor by pressing down on the tab on the top of the connector. DON'T PULL THE CONNECTOR BY IT'S WIRES!!! Pull back the vinyl tubing that covers the 4 wires going to the connector. Gently pull on each wire with your fingers. The wire should have no stretch and feel solid. All the wires should feel the same. If one or two of them feel weak and stretchy chances are you have a broken wire. Is what happens is the wire breaks inside the insulation so it appears to still be connected. Why do the Temp/Baro sensor wires break in the first place? 1.The problem with the current Polaris wiring is too short and Polaris used 7/32 stranded 22AWG wire. This wire has a very low strand count and should not be used in applications where vibration occurs. 2.The next problem is the mounting location of the sensor it is in a vibration prone spot on top the air intake tube going from the air box to the throttle body. Next time you're bored take the seat off and rev it up in neutral. That intake boot and sensor vibrate to the point where it looks blurry. The combination of these engineering flaws causes the cable to break in a big hurry. The Polaris repair kits keep breaking. Why? 1. The replacement kits from Polaris use the same 7/32 strand wire that can't withstand vibration. How do I fix this dang problem once and for all: 1. After multiple replacement kits failing and multiple hack jobs to the replacement kits so I could go riding for the weekend I finally came up with a solution. I bought a pile of connectors and sockets and built my own repair harnesses using 65/36 18AWG wire with a thick silicone jacket. This wire is the same type of flexible wire used on things like multimeter leads. It is some really good stuff. Then I use sealed butt splices to connect my new harness to the factory harness. Any questions please don't hesitate to PM me. I will be more than happy to help you out.