I have a 2000 Ford f150 4.2 engine ,195k odometer.. Manual transmission

The issue I'm having is that as I'm driving the vehicle when I reach a certain speed in first gear I can get up to about 5 mph and then the car will start jerking violently. When I go up to 2nd gear I can make it to about 10 mph and then the car will start shaking violently. When I shift the vehicle to third gear I can get to about 20 miles per hour before it starts shaking violently. In fourth gear I can get to about 30 mph and it does the same thing. This morning on the way to work it was driving just fine and about 5 to 10 minutes from reaching my destination it started doing the violent shaking again I don't know if it's the catalytic converter or something simple like a sensor or something.

I've already replaced the purge control valve, as well as the EGR valve on the truck. I've also checked the spark plugs and replaced them.

Any knowledge or insight from you guys will be completely helpful because they already want $900 for a catalytic job on this truck and I cannot afford that.

 

Your truck is an OBDII model. You need to plug in a code reader and see what it says.

A bad cat won't cause what you're talking about.

From your description, it sounds RPM related--

Have you noticed if it's roughly the same RPM each time?

Any work to clutch or transmission?

 

I have a scanner and I'll use it to check the RPMs but if it is an RPM problem what are you suggesting

 

Does the scanner report OBDII codes? That's what we're looking for.

Once you have that, then the RPM issue can help with diagnosis.

 

Yes it does

 

Post the codes.

 

P0300
P0320
P0455
P0401
P0174

 

P0300
Random misfire. I see you swapped plugs, what about COP or wires?

P0320
Engine speed circuit problem. Similar problem here:
https://www.ford-trucks.com/forums/6...e-jerking.html
Check connections, anything to do with ignition, including COP and related wiring

P0455
EVAP leak. Check gas cap and filler neck, plus charcoal cannisters and connections including all lines to intake for vacuum or fumes.

P0401
Insufficient EGR flow. Related post:
https://www.ford-trucks.com/forums/2...r-flow-26.html

P0174
Too lean. Check for vacuum leaks which could also be related to your EVAP issue.
https://www.ford-trucks.com/forums/7...ode-p0174.html

 

Could you spell out the "COP"

 

Coil over plug. I'm not sure you have those, but all connections in the ignition system should be checked.

 

I'll give it a look tomorrow, I'll tell you what I find, thanks for everything

 

Check your fuel pressure
The bucking and jerking sounds like low fuel pressure to me
Those codes are some trouble for I/M compliance, but are not the jerking problem IMO

 

Turned out to be the crankshaft sensor, drives like brand new now