I AM HAVING PROBLEMS WITH HIGH CO LEVELS CARBON MONOXIDE I HAVE CHANGED THE CATS/LAMBDA SENSORS AND AIR FILTERS ANYONE GOT ANY IDEAS HOW TO BRING THE LEVELS DOWN THE CAR IS AUDI 80 B4 1994 2.6 V6 213K MILES

are you runnin rich .... injectors possiblly if it hasn't been done before/yet

check that the vacuem is applied to the fuel preasure regulator. also that no injectors leak(unstable idle). MAF is clean and functions right. thats for starters.
check the tip of the tail pipe, is there a black ring around the outer endge?