Hey folks! So I was driving home from my in-laws the other day and when I was about 10 minutes from home I noticed my Ram was acceleratimg weakly up a hill. I didn't think anything of it but then a few nminutes later it suddenly stumbled with minimul throttle. It got worse and worse and by the time I was about home it would barely get up to 20 mph and took forever to get to that speed.

It will only accelerate when the RPM's are below 1500. It starts fine, idles fine, and actually pulls okay for the brief amount of time it takes to get up to 1500. If I put it in nuetral and rev it, it won't rev above 1500 that way either. This is all out of the blue. The truck has run perfectly and been problem free for the 2 years and 10k miles I've owned it.

To give you a taste for how it feels, it actually feels pretty similar to when the traction control goes on when I'm driving my 2006 Mustang. Like something is artificially holding the engine down to 1500.

I checked all the intake items and there is no clog. The exhaust is not pinched. I heard the cats on these can get clogged so I unhooked the 02 sensor before the cat to see if that would provide any relief. No difference. Could the fuel pump be dying out? Or did I trip some sort of fuel shutoff somehow? Thoughts? Thanks for the help!!

Here's a photo of my truck. It is stock other than some 285/70/17's on 2004 Rams wheels and a muffler delete.

 

Did you just unplug the pre-cat O2, or did you physically remove it from the exhaust?

 

it sounds like to me that the cat is totally clogged

 

+1 Sounds like a clogged cat...

 

I physically unscrewed the o2 sensor.

 

Check the fuel pressure with a gauge.

 

"This is all out of the blue".

That doesn't sound like a plugged cat to me; that would be more gradual.

Two things that come to mind are water in the fuel, or a Throttle Position Sensor. I lean more toward the TPS since it starts and idles fine right up to 1500. Put a meter on it and see if it's putting out the correct values.

 

my brother went into wal mart came out and his truck ran like crap he said and when we looked at the cat it was clogged he said it ran fine then he came out and he had a similar problem the truck would rev properly...so my vote would be cat but no guarantees lol

 

I'm wondering how his cat became clogged while he was shopping.

 

When my cat messed up on me out of the blue. I was in San Francisco all day and while on the golden gate bridge on my way home, it wouldn't go past 40 mph.