colleen's silver bullet

I have a 2004 4.6 with mac cat back H pipe and mac cold air it will miss only at idle and will only throw check engine light once and a while and then it goes off.When i put it on a scanner it show idle miss brought it to ford and put it on the oscilascope and it shows no problem.The miss only started when it put the cat back on. HELP

lizzyfan

Please go here https://mustangforums.com/forum/4-6-modular-mustang-7/