What are some things to check for rough idle on a 4.6L? I changed plugs and that seemed to help quite a bit but it still a little rough. No trouble codes from the computer.

MAF ?
Fuel injectors ?
Throttle body dirty ?
Fuel Filter ?

 

How many miles?

Do the easy/cheap first. Fuel Filter, MAF and TB cleaning.

The next steps after that would be COP's and fuel injectors.

 

198k miles. How much risk is there to damaging the MAF wires with the cleaner?

 

None. Dont touch it with your fingers. Some guys use alcohol and a q-tip. I've always used the CRC MAF cleaner with no issue. I never touch it with anything. just spray it.