bwFX42006

I have a 2006 FX4 with 56,000 miles on it. It's got a K&N CAI and I took a short trip into town yesterday and all of a sudden the truck started idling really low at the stop light and then the check engine light came on. Then on the way back home it started lurching forward and cut out. I cleaned the air filter today, sea foamed the gas tank, disconnected the battery and the light went off but it still is idling very low, around 400 RPMS. Any ideas on what could be wrong? I bought the truck with around 40,000 miles on it and haven't had a problem until now, hopefully nothing serious but maybe someone has had similar issues?

sinclairgraphics1

Man, I've tried replying to your post about 3 times now and says I'm not logged in every time! Anyway, try cleaning your throttle body, this will help immensely. Use a can of throttle body cleaner. Also clean your MAFS as these can get dirty can cause issues with air/fuel ratio. Check your Fuel Pump Driver Module under your spare tire. These corrode very easily since they are bolted right to the frame and cause all kinds of drivability issues. If none of those are the cause you could have an ignition coil out or bad spark plug. Start with the easy stuff and move on from there. Good luck and let us know what fixes it for you!

bwFX42006

Thanks, thought it could also be a bad TPS sensor as well. Praying to god that it s not the plugs though!

wyoming

My truck did the exact same thing, cleaned the throttle body with some very specific "Throttle Body Cleaner". Did the same thing for the maf sensor, with MAF cleaner. Ran perfect after!

Mikegfx4

my truck was doing a similar thing after disconeccting the battery. There was a procedure in the manual that must be done every time you disconnect the battery or your battery dies. I dont remember what the section was called however. Sorry good luck!

bwFX42006

thanks for the suggestions, just curious, what does everyone's truck idle at while in drive? mine's idling between 400 and 500 rpms in drive and around 1200 in park.

sinclairgraphics1

For the TPS sensor you have to buy a whole new throttle body because they do not sell it separate since it's part of the TB. I bought one brand new on ebay for under $200. The stealership wanted $700 for new TB and installation. It took me less than 30 minutes to put it on. As far as the plugs go, I did mine and it took 3 days. I broke 5 out of 8 plugs! The last plug would not come out and I had the Lisle extractor tool. I had to call Lisle Tool tech support(they were super helpful)to have them walk me through getting the last one out. I had to use a hammer to hit the Lisle tool into the plug head so it would bite in and have the extractor work properly. If I were you I would change them asap. You don't have that many miles on it. Mine had 146,000 and no one had ever changed them before. Watch videos on Youtube before doing this to see what you're up against.

sinclairgraphics1

That sounds about right, mine idles in the 500 range. When the throttle body was dirty it would just die whenever I slowed down at stop lights. Once I cleaned it that wasn't a problem. I ended up replacing my whole TB a month later because of a bad TPS sensor.

bwFX42006

sounds like i'll be cleaning that throttle body out this weekend. Plugs will probably be next on the list as well!