Just bought a 2007 King Ranch model with 5.4 engine, took it home, and on 2nd day was towing load to Jasper, Texas from New Waverly, Texas(we're moving!) Half way there went into what the owner's manual calls "limp mode"....engine light blinking on dash, A/C stops blowing cold air, engine runs rough, can't get but 45-50 mph at best....feels like is going to die and stop on the side of the road??!! Read all about it in owner's manual....says getting hot and one cylinder changes to air flow to help cool engine, but no heat registers on heat gauge, engine does not smell or feel hot. Immediately took into dealer(AutoNation of Katy)....very nice said would take care of it....had for a week...replaced "coil to spark plugs"....I picked it up and got on freeway and truck did exact same thing happened immediately??? Took it back...got the salesman and had him drive and did same thing, so had a witness!! Took to head of Maintenance/repair and told story and he said no problem we'll take care of it....kind of miffed though, since I have to drive 78 miles one way and wastes a whole day, and one would think a mechanic would "test drive" a vehicle after "fixing same".....
Am just wondering if anyone has had similar problem and has a suggestion??? Have talked to other King Ranch owners and some have said that "after market computer parts screw up the whole thing"....don't know if it has after market computer parts, but was a suggestion...John T

 

How many miles on it ? You need to mention stuff like that..

 

108,000 miles....John T

 

Just got a call that they had replaced the catalytic converter....does this sound right?? John T

 

Headed to AutoNation today.....hopefully for last time on this problem....John T

 

Cats could do it. Also a simple throttle body and MAF cleaning can take care of it. That's what it was when my truck did the same thing.

 

Did the engine failsafe message come up on the screen on the dash where the mileage is? The Lariats and King Ranchs will spell it out when they go into engine failsafe mode.

Engine light flashing means there is a misfire, and with that kind of mileage it's probably on the original spark plugs. They probably need to be replaced as well. Ignition coils also a possibility, did they replace all 8, or just one?

It's a very good possibility the converter was causing the issue as well.

When i bought my 06 with 90k, it came with the 30 day warranty, and it was having similar issues with misfiring, and they replaced 1 plug, and 2 coils, when in reality it was time to replace all 8 coils and all 8 sparkplugs, but of course they weren't going to do that, they just fix it good enough to get it on the road.

These engines have a big problem with sparkplugs breaking off inside the engine when they are being removed (lots of info in the sticky at the top of the 2004-2008 page), i paid the dealership over $600 to replace my sparkplugs, but did my coils myself, and then did the sparkplugs again myself.

 

Find out when the last tune up was done

 

Thanks ya'll.....picked the truck up today and it runs fine at this point. Wish I had known about the replacing all spark plugs and all coils....since we have a warranty, I was hoping not to use it for a while....and I'm guessing that replacing spark plugs and coil is not covered anyway. Will ask about the tune up....when should spark plugs and coils be replaced?? How many miles?....John T

 

100k... If your's has not been done .. Your 8k over and may be the cause of your clogged cat.