Ok so no iridium spark plugs check, old filter was in pretty good shape, spend $50 on K&N filter so i put the old filter back on.

it doesn't have an economy gauge, should it????

where could i find the vacuum diagram (dont have orignal manual), they seem kind of brittle and would like to replace them correctly, like i said i had some "expericence mechanics" work on her and i have a feeling they just pluged the vacuum hoses anywhere, but this problem has been happening since before then, so i'll do my best if i can't do it, i'll take it to the MB dealership when i can get the $$$ to do so....

Also this problem doesn't always happen, just when she feels like it , and sometimes will go away while driving the car, could that change the problem??