I have a 2104 MDX and I was able to use the spacers for the exhaust. On the front cat I did not have any real issues with installing the spacer and the min CAT in place of the O2 sensor. I did have to move the wiring a little bit to make up for the change in place of the sensor on the pipe but other than that it worked out ok. For the rear cat I did have an issue where the design of the car prevented me from using the complete device in the exhaust. I was able to use the O2 sensor section as just a spacer for the sensor. This worked out as fine as the sensor section has the same thread that the sensor so there were no issues with installing it in the pipe. I don't think there would have been room in the area for even the straight one or the 45 degree one. As the title goes the engine light is now out, and I was able to pass emissions inspection with them on. This item works as designed even if it is only used in parts.