[Cakeman]

Own a 2004 Sun Voyager and the check engine light was coming on. The Workhorse dealer told me the only sensors on that control that are oxygen sensors on the exhaust. Had to replace 2 of them and it went away but the check engine light came on during the next trip. I was in the mountains and turning off the overdrive for going down the hills and thought that may have caused it the second time. I explained to the dealer and they found some goofy codes but no bad sensor, did find a loose fitting on the exhaust at the manifold so they tighten. Next trip same mountains still turning od off and not light.
For what it is worth, the workhouse dealer told me that their are only 4 sensors on the exhaust system that controls the check engine light.
Cakeman