My truck is bucking and it seems to be happening near "no load" conditions and usually around 40ish mph. It feels like someone is pressing and releasing the throttle very quickly. Also, there are times when I'm lightly accelerating from a stop and I can hear the engine rev up and down but there is no or minimal bucking. It never seems to rev any higher that what I have the accelerator at. No problems when I'm heavier into the throttle. I have about 40k miles on the truck and have never had any issues with any of the emissions stuff (no egr probs, no turbo cleaning, no dpf pluggage). I did a search in the forums and the TSB's but didn't really find anything that sounded like this. Any ideas? I have no CEL but haven't plugged in the code reader to see if there is a code buried in the system. I'm thinking something is going on with the TPS, maybe. I don't want to think there's something up with the turbo .

 

I don't know that something would be bad with the turbo at this point. Do you have the EB engaged when it does this? Tow Haul mode?

 

I ran to work with everything in 'normal' mode and had no issues. Then I tried with the exhaust brake on...nothing. Then I tried with tow/haul on and thought there was nothing for a few starts. Then, maybe just a subtle indication of it. I will have to try some more to see if it happens when either the EB or tow haul are selected. Today's test was too inconclusive for me. I'm going to go plug in the OBD to see if it shows anything, by chance.

 

I find at low speed in T/H and EB engaged, it has a hard time selecting the right gear or locking the torque converter ready for the EB to engage, but drops below the speed too quickly. I get a good jerk and then coast. In slow speed stuff, I kick out the EB just so it doesn't try to do that.

 

Exactly! X2 ^^^

 

If you find a amswer let usz know mine just started same thing. I can almost get it to happen at will. Between 40 and 45 easy aceleration. Not sure what it isz. Dealer is blaming o2 sensr thatsnot warantied

 

Exactly! X3

 

Any update? as mine just started the same thing but threw a code of the P2262. So I'm thinking mine is turbo but would like to know what you found out?

 

Update on mine, cleaned the codes out of it and started driving it like a madman. Within of a couple of trips, no more codes and no more bucking! So for now I'm good but would like to know what your out come was?

 

Mine has been doing the same thing sporadically. Did your check engine light come on when it threw the code? I haven't checked for codes.