RevCo

Howdy folks, I have a slight problem when maintaining the gas peddle at a steady speed. I can feel the engine increase (very midly) in speed then drop back to where it was. There is no noticeable changes on the speedo/rpm gauges. Anywhere I should look into? My guess is maybe the TPS and slanted towards using a cleaner that might cure this issue. Like I said, its very very mild but I can feel it on the gas peddle. Thanks in advance for any suggestions...