What can you tell us about the throttle module? White Sticker, Yellow Sticker, or a full blown Xemodex modification? On a '99 or 2000 with those symptoms the throttle module is always a suspect but a bad or dirty MAF sensor can do the same thing. The throttle module will typically trigger the ETS l...

Lee,
Thank you again. I will try the cleanings first.

Thank you for your response. This is a non turbo. Is the throttle module bolted to the intake manifold? If so, it has a small round white sticker. Is the MAF sensor attached to the air filter housing? Can it be cleaned, and does the throttle module need to be removed to be cleaned per your comments?...

My 1999 S70 with 115,000 miles will occasionally experience engine stumble under light throttle and will stall at idle occasionally. The check engine light does not come on. The Volvo dealer was not able to replicate.