What is your question?
When I start the vehicle it has a rough idle and when I push the throttle down the vehicle shudders and is slow to accelerate but smoothes out around 40-45mph I changed the spark plugs and gapped them correctly I ran diagnostics and it came back with change the plugs, EVAP sensor, Ho2s sensor. Plugs are done but do I need to reset the system? And the EVAP sensor is what I'm told but they also say to check the fuel cap mine seems like it is really easy to unscrew even when it clicks when closing just doesn't fit like a functional fuel cap though it does click when tightening it just easy to unscrew
What makes this problem better or worse?
It comes and goes but mostly when acceleration up to about 40mph then smoothes out a bit but there is shaking in the steering wheel at 55mph+
How long has your 2005 Cadillac STS had this problem?
Just bought vehicle 4 days ago guy said it was the EVAP sensor though I read that it could be the fuel cap mine feels really easy to unscrew but it clicks when tightening it
