Just 2 years ago this van passed with flying colors this time no go.

Passed the 15 mph failed the 25 mph HC and CO

HC max is 103 I measured 190

CO max is 1.10 I measured 1.12

the only thing I have noticed is that my throttle position switch has been acting up recently, but that is at low rpms. any thoughts or suggestions will be greatly appreciated. I have a new TPS and will install today also I didn't do a plug or oil change prior to the test, would that matter or help?

TIA,

paul rogers

85 westy