Chug at start, "bouncing" tach when key turned to "on"...

just found this thread. My tach does the same thing when i turn the key to the on position. it does that little bounce thing buy my car runs fine there is nothing wrong with it so idk

Quote:

---

Originally Posted by SlowNA06

See what your EGR is doing at idle. This strikes me as a vacuum leak, though, so check all your connections.

Also, try unplugging the MAF and seeing if it runs better.

---

vac leak should have coded an o2 for lean mixture.