2007 Mustang GT problems

[Okregency]

U7145

2007 mustang GT manual
JLT intake, 09' intake manifold, flowmaster american muscle series ehaust.

I had to change my spark plugs out after 19K miles. I have changed to the autolite HT1 with the .045 gap.

The throttle rev's high for 10-15 sec's or more before getting below 1700.
The mechanic said that the a/f mix is very rich. I go any where from 20-27mpg on the highway making the same trip on the same roads.

[mikel]

What tune are you running?

[Okregency]

I am running the JLT intake tune. I live in oklahoma and so I run 91 octane, as it is the highest I can get.

[v6procharged]

mine would do that same thing when i put on new intakes and it had a vacuum leak and the IMRC's were disconnected... idk if the newer mustangs have IMRCs but i would check for a vac leak.

[Okregency]

Already did. It spent a month in the ford house. They found an intake manifold leak and replaced it. That is why I am running the new 09' intake manifold. For a few weeks after I reinstall the tune it doesn't have the idle problem but it returns.

Also, what is the best dyno tune shop in Oklahoma?