First post, did some searches and didn't see any similar posts, so thought I would start a new thread. Have an 09' F150, supercrew, 4.6 with about 100k miles on it. I'm experiencing a huge loss of mid-range power. 1500rpm to 2500 lose all power, even with the truck empty I have to push the pedal to the floor to get it to go up hill. It's at the shop now, but curious if anyone else has experienced this.

Basic stuff has been checked, and the computer did show an o2 sensor needs to be replaced. Oh- already replaced the tranny at 75k miles, so it's still pretty fresh.

Thanks

 

In general you start by installing latest software, reboot the sytem ,check all sensors.

 

Tranny at 75k???? Good lord!

 

Yup, pretty crappy. I don't really haul anything, and the mileage is pretty much all highway!

 

Will it downshift when you floor it?


O2 could be really fouled. Are you running a K&N filter, they will foul the o2 badly.

 

A K&N fouls the MAF, not the O2's.

With 100k, if you haven't changed the spark plugs yet, it's time. Also, have you been keeping the fuel filter changed?

What exact numeric P-code are you getting?

 

Thanks for correcting me GLC. The sensor which is between the airbox/filter and the engine's intake gets gooooooberd when using oil style filters.

 

It will downshift, eventually, but it's pretty violent. O2 sensor will be replaced this morning, then further diagnostics. Nothing else is jumping out at the tech, so they will check a few more things.

 

plugs, fuel filter & general "tune up" was done aroung 75k when the tranny was replaced.....I'll find out what the code is when I get over to the shop.

Thx!

 

Shot in the dark...

but could it be something VVT related?

 

Outta curiosity, we'un's talking 2V or 3V??

 

So, the update from the garage is, after a compression test, there is quite a range! As low as 89 and the highest being 145..... 175 being the goal. So, they figure 4 of the 8 cylinders are low. Further diagnostics to be done. At 75k a new tranny and 100k a new engine???

 

Man, you got a bad one. It happens.

 

My 1978 E-150's 3 speed tranny only lasted 80,000 miles.

Alltho the 4bbl-351 cu in ran like a top until I put her down 11 years later.

11-12 mpg on the e-way with no tow.