Just swapped engines..erratic idling..

[93Leg5spdTurbo]

About 2 weeks ago, I swapped out my ej22t (after throwing a rod:( ) for an identical one with about 80k on it.

Now when it's warming up, the rpms drop so low that it studders like it's gonna stall out...then it revs up to about 2000 and repeats this over and over again.

My check engine light is on, and it's throwing a knock sensor code. But I can't see how that relates..

I used all my sensors from the old engine. The old engine would idle low and studder here and there, but never did anything like this.

Any ideas?

[Laura]

umm. . . replace the knock sensor. . .

This is the exact same thing that happened to me and sence we've replaced and put in a good knock sensor, it completely quite doing that.

How it relates? The knock sensor is cracked, so (how I interperated it is) it's grounding itself. . . full power isn't being reached.

Do it. . . you'll be happy.