I have a 2008 STS 4WD that has been surging lately. It has 106K with no previous problems. It started to become worse today and the check light is starting to flash intermittently. The light doesn't stay on so I cannot check codes. It appeared to get better when it warmed up.

Thoughts?

 

I am looking forward to some pictures up here.

 

Actually, the codes should show. When a "check engine" code pops up, then goes away, it will show like historic. Go to any auto parts store, and they should be able to pull ALL the codes - current and old. If not that, your local Cadillac dealer/shop should be able to pull your codes.

TS

 

Flashing service soon light indicates condition that will damage cat converter. Generally it's a misfire and code(s) should be set. At the mileage car is due for spark plug replacement. It's a place to start.

 

Thanks very very useful.It is a very useful article.

 

I have also the same method and work in my work shop for a number of cars.Actually its good to surging your car because with this your car works properly.