Buick Ultra Service Engine Light

[ellis479]

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

[HotZ28]

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.

[ellis479]

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

[HotZ28]

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

[ellis479]

HotZ28,

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

[HotZ28]

Originally Posted by ellis479

HotZ28,

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

Most emission repair shops use one of these, or a similar brand.
http://www.youtube.com/watch?v=ozs2lf70Buc

[ellis479]

Hello,

[ellis479]

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