This may or may not apply.... I have an 03 TA. It was a known issue that the paint on the inside of the fill neck of the tank would flake off and fall into the tank. The paint chips would cling to the screens on the petcock and drive you nutzo. Drain the tank and pull the petcock and see if the screens have any debris on them...
Again, this may be a non-issue with an 05, but it's a lot cheaper than replacing coils or other electrical parts.
And the Seafoam suggestion is a good one every 5-10 tankfuls, regardless.....
