FICM replaced, idle issues

[averagejoe]

About a month ago I was having cold start issues with my 2004 f-350. It has the 6.0L in it. I took it to the dealership and they told me the FICM was bad. I had them replace it and they said they loaded it with the most current software. Since I picked it up I've been having several new issues that were not present before. When I start it cold it will idle for five minutes or so, then idle up to about 1,000 like normal, however, it will begin to have a very rough and sometimes surging idle, stumbles and misses. It will also not drop off the high idle when the brake is depressed. Eventually when it warms up the idle does come down, but still surges now and then. Even when it's started warm it tends to go to he 1000 rpm high idle and wont drop when the brake is pressed. Any ideas? I've had it back to the dealer twice and they are scratching their head. No codes present.

[Dave]

EGR valve plugged in?

[averagejoe]

Yes it it.

[sinner6.0L]

check the harnesses going into the ficm. the connectors are very delicate and it's not hard to break a tab or two during ficm replacement. a connector that's coming unseated can cause various drivability issues

is your 04 an early 04 with the ICP in the rear? if so I'd be looking at that too

[averagejoe]

Thanks, I'll check the harness out. It's an early 04 so I'll check the ICP too.

[averagejoe]

Sinner6.0L, my truck was back in the shop when you posted. Not long after I read your post they called back telling me the ICP was bad. I went ahead and had them replace it. Seems to have cured all my concerns. Thanks.

[sinner6.0L]

glad to help, the ICP leaking is a common concern on the early trucks