Buick Ultra Service Engine Light

Hello,

I have a 2003 Buick Ultra with the 3.8 supercharged engine. I'v been having an issue with the service engine light. My OBD tool shows an emmissions system alarm which covers a lot of territory. I changed the gas cap and it worked for a while then failed, so I tried an OEM gas cap. This worked for a while, now it comes on for a day or two and goes off about one a week. This is probably a very small, simple problem, but the yellow light sure bugs me! Could an O2 sensor cause this type of alarm? This engine has about 90,000 miles. Any suggestions............Thanks ellis479

You need to give us a P0XXX code so the issue can be narrowed down somewhat. If your scanner is not capable of displaying codes, take it to Advance Auto, or AZ for a free scan.

Right now it is not displaying a check engine light. the last two times I checked it when light was on, it displayed DTC PO 440 Evaporative Emission System. I have a pretty nice OBD tool it is an Innova 3100, it shows a wide variety of DTC's. Thanks Ellis

Sounds like a small vacuum leak somewhere. These can be hard to find without performing a smoke test.

HotZ28,

How do you run a smoke test, and where would be a good place to start looking?? thanks ellis479

HotZ28,

How do you run a smoke test, and where would be a good place to start looking?? thanks ellis479Most emission repair shops use one of these, or a similar brand.
http://www.youtube.com/watch?v=ozs2lf70Buc

Hello,

Problem has been solved, small leak, Thanks for your help.....ellis479