Just thought I would add this in from today. A little history; After installing a foam filter on mine it started dying sometimes when going from drive to reverse and touching the gas. After finding oil on the sensor and cleaning it, it quit doing that. Then on the last camping trip last week it started doing that again so today I pulled the sensor and sure enough, it was covered with filter oil again. Gave it a good flush-cleaning with the cleaner and back in it went. This time when I cleaned the big-Uni in the box I used extra paper towels inside and out to get all excess oil out of the filter. I hope that does it.. but it does say that we all need to check and clean these sensors once in a while. Also..may be my imagination but after doing so it seems that the exhaust also smells richer too. Not sure why it would..