96 Blazer LS Does anyone else have this problem??

Hope someone can help out a little. Here's my story. 96 Blazer LS 195,600 miles. Bought it used in 1999 with 42,000 miles. I make sure the oil is changed regularly, etc. Recently had a tune-up (June 2004) Did not have the radiator flushed. Service engine light is on. Really stinks when idling, and when you shut the engine down. Pick up is not bad - does have some hesitation but not all the time. Oil filter lines and gaskets have been replaced. Also had a motor mount done at the same time as oil filter lines and gaskets. I know it has a lot of miles on it. I LOVE this car, not ready to give it up yet. My husband read an article in a local newspaper that described the symptoms to a "T" but he can't remember what the article advised to check. Is there some kind of intake valve I should mention to my mechanic.
Thanks in advance to anyone that can help.

Jackie

Ok, what does it stink like?

Does it smell like rotton eggs?

What did the tuneup contain?

List all parts replaced with the tuneup.

It doesn't really smell like rotten eggs - more like dirty exhaust?? It does not smoke, though. Here are the parts that were replaced when the tune up was done.
Spark Plug wire set
6 spark plugs
distributor cap
ignition rotor
pollution cont. valve
fuel filter
carb. cleaner
injector cleaner

Thanks,
Jackie

Also, the oil lines were replaced and new gaskets installed. Air filter was changed.
Jackie

Have you catalytic convertor back pressure tested and have your truck hooked up to a scanner for sensor monitoring.

Will try that on Monday, Thanks for getting back to me.

Jackie