Following routine maintenance on my 1997 540i 6 Speed with 110000 miles:

1.) Changed the oil (5/30 Syn) and filter
2.) Spark plugs (NGK BKR6EK)
3.) New air filter
3.) Cleaned my MAF with electical contact cleaner
4.) Cleaned the Idle Control Valve with carb cleaner

Now my mileage has dropped by about 1 mpg around town and my idle is rough. Any ideas??

Also, I did a code scan and everything is clear.

THANKS!
Bill

did you gap the plugs properly?

Non-Adjustable Plug Gap

ZOMG YOU SHORTED YOUR MAF!!!!!!111one J/K I dunno but it might actually be the MAF even though it didn't throw a code.

check your tire pressures