2000 mercury mountaineer

[Nyblue7]

Hello, I'm not sure if I should be posting this here!?!? Sorry in advance...Having an issue, where my truck will rev perfectly fine to 3000-4000 rpm while in park, but as I'm driving it, will only go to 2000 rpm. Even at 65-70 mph...Any help will be greatly appreciated.

 

[C420sailor]

In all gears? Or only at highway speed? What happens when it reaches 2000rpm?

 

[Nyblue7]

In all gears? Or only at highway speed? What happens when it reaches 2000rpm?

It gets up to speed, but just stays at 2000rpm

In all gears? Or only at highway speed? What happens when it reaches 2000rpm?

It literally tops out at 2000rpm while I'm driving..

 

[C420sailor]

So if you’re cruising on the highway at whatever speed 2000rpm gives you, and you put the pedal to the floor...

It doesn’t downshift?

 

[410Fortune]

Is this a v6 or v8 truck?
Does the tachometer stop at 2000 rpm or the engine will actually not rev higher?

 

[J_C]

My first guess is check the fuel rail pressure.

 

[donalds]

Sounds like a catalytic converter plugged up imo