Hello All

My 98 S70 (117,000 miles) non turbo sometimes idles rough and I can smell the excess fuel as well.

This only happens when I run the car, park it and then start it for a couple of seconds (pulling in or out of the garage) and then leave it sit for the night. Everytime i start the car the following morning, I can tell by the engine rev and smell that there is something not right...

I took it to my volvo dealer who saw the problem and "diagnosed" it to be a bad vacum hose, but the problem pesisted. Then i took it to a private Volvo mechanice who perfomed the tune up and told me the old plugs were not the oe specs for my volvo!!! However, the problem still continues.

This is more of an annoyance problem, only happens when i run the car for a couple of seconds, and when this does happens i can let the car run for a couple of minutes, the excess gas??? burns off and the car rides great!!!!

Do I have a bad o2 sensor or mass air flow sensor????

Any and all suggestions are appreciated!!!!