Engine light on

Dear Hyundai Group,
My 03 V6 Gl Sonata's engine light came on for the first time today. It is not blinking; just on. I had my car tuned up and transmission/engine oil
changed, fuel injection clean out and new tires (1,578) last month. My car has 80,000 miles (all highway) on it. For the past 3 months I was given a company truck to use so I only used my car on weekends. One time I went without driving it for 2 weeks and it would not start. I thought it was the battery but it turn out to be the gas not in the line so I pumped the pedal and it started up. It's been fine ever since. I do noticed that after my car service (tune-up injection cleaning) that my car runs rough (vibrations) and my gas mileage went from 28 gpm (highway) to 23 gpm (highway). I called the dealer who tuned up my car and I am bringing it in for a diagnostic (99.99) + whatever it will cost to fix the problem. How would I know it is something related to my recent maintenance? It seems whenever I get something preventative done with the car, a new problem occurs. This was the case with my last car (Chevy cavalier). But that car is still running at 385,600 miles!! Here in CT. we recently had a snow storm. The top of the snow was Icy, therefore it was hard to shovel and get out of my driveway. Well, after shifting back and fourth, my car was able to get tout of the 6" inches of icy snow. As I was baking out of the driveway, I noticed a black piece of plastic on the ground where my car was sitting. This piece was a shield that was covering the oil filter area. I noticed that 2 pieces where missing. Is this the culprit that made light come on? Is it okay to drive without? I will keep you updated. But in the mean time any comments would be greatly appreciated. Thank group.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

You're kidding right? They tuned up the car, it now runs worse, and they want you to spend a hundred bucks to find their problem? You should have gone right back to see the service manager and have it corrected N O W ! ! !

Now it may be too late. That should have been done right away. Damned if I'd pay the 99.99.
You need a new shop, IMO.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Have you recently filled up with gas?
My CE light often comes on due to the gas cap not being tight enough or from over filling.
Chris
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.