99 Accord 5-speed which I just bought 3 days ago. Noticed under acceleration and decelerating a lunging, almost as if it needed the fuel injection cleaned badly.

Also, while on the highway where it's most noticeable, a slight vibration which I feel about every 5 seconds, consistently. And it's very subtle, not terribly noticeable, but I can feel it.

Also, the check engine light is on, haven't run the codes though.

My untrained mechanical ideas are maybe motor mounts??

 

Get the code(s) to help identify problems. Stop by an autozone, have them read the codes, then post the actual code on here (like P1234).

 

Grab the valve cover & shake it to check the engine mounts. Loose mounts won't set off the CEL.

Has it been sitting in a driveway with a forsale sign for very long? Stale gas? Or maybe gas that's NOT winter-blend? If you're lucky it might get better when you use the gas & refill.

 

The CEL code is P1457

Any chance this may be it?

 

P1457 = EVAP system leak; in the canister section of the EVAP system

That "shouldn't" do anything that you can feel. There's a thread about it over in the DIY section.

However... If you're in the habit of over-filling the gas tank, the charcoal in that EVAP canister might get saturated. Then that might cause both the lunging and the P1457.