OK, I haven't been around for a while due to hurricane Rita, but things are finally getting back to normal.

The truck in my sig seems to have some power lacking issues when towing ~10K pounds (see gallery for rig). At any rate, I have a hard time holding OD at 65 mph on flat terrain at near sea level (that's without the ATV's). The truck is basically stock with the only possible impact in this situation being 285 tires.

Truck has new air filter and fuel filter, running 87 octane gas.

I moved from an F150 4.6 to this truck, so it felt like I had all the power in the world. However, after recently struggling in the mountains, I started to question if something was wrong. After talking to my dad, who has a '99 F350 V-10 SRW and pulls a 14k+ 5er, I'm really concerned. He has no problem pulling OD at 75mph with his rig with less hp.

The truck runs great. No missfiring, no stumbling, and it feels like a beast unloaded. With >130k miles my first thought was the cat was starting to plug. I guess this is possible, but the one vehicle I've had do this went from fine, to wouldn't hardly run, in just a few days.

So I'm reading through posts and see that there were four possible PCM programs from the factory. Since this truck came from CA, is it possible I have the worst program performance-wise? If so, what program do I need? I assume there are codes or names for each program. As another option, could I just buy a performance programmer which would overwrite this factory code?

Is there anything else I can check or any other suggestions? I've read numerous posts about the differences in power between seemingly identical V-10's. This has to be due to PCM or some other mechanical/electronic explanation.

Enough rambling. Sorry for the long post. Any advice, suggestions will be greatly appreciated.

 

What is YOUR history with the truck? Is it new to you?

Did this struggling feeling happen on your first towing trip or are you comparing the performance from another trip you made with this truck?

2 things come to mind first.

Winter blend gas.
Poor state of tune. I know you stated the air & fuel filter are new but how's the oil, the tranny fluid, diff fluids, emissions crap etc. etc. ?

If this poor performance is altitude related...well...I don't know.

I DO know you do NOT want to add a tuner until you know for certain that your truck is in a perfect state of tune.

I asked the question a few years ago as to which PCM was the best. That's one hard question! What is your father's PCM code? We...on second thought...he has the 99 V10. Different animal.

 

I've had the truck for two years. As far as I can tell, there has been no performance change in these two years. I normally have two ATV's loaded in the back of the truck on a special rack (see gallery), plus the trailer; so I assumed the truck struggled a little bit because of the load. I recently took the first extended trip without the ATV's, and the truck still struggled. This is what got me asking Dad how his performed towing, and thus I started to realize something was wrong. Like I said, I graduated from an F150, so I didn't notice right away that there was a performance problem.

The transmission fluid and filter was changed about 10k miles ago. I have checked both differentials and the transfer case, and all is good. The only thing I have not done since buying the truck is change the plugs, which is next on my agenda. I have read all of the plug posts, and will take the utmost care in performing this operation. That said, this could well be my issue. I haven't pulled a COP, but it wouldn't be far fetched to think this truck may have the original plugs. At 130K+ miles this could definitely be hurting me.

I have not checked any of the emissions crap. However, the truck has no miss, no sluggishness, and seems to be in a perfect state of tune. It just seems to be a little low on power compared to other V-10's. This is what got me thinking PCM.

At any rate, thanks for the reply. If time permits, I'm going to do the plugs this weekend and see if that makes a difference.