2003 Chevrolet Malibu • 160,000 miles

Help! I have an 03 Malibu. 3.1 liter. I noticed a collapse vacuum line ( the u shaped hose on the PVC tube) I replaced it. Now it shifts from first. Then revs high like it is slipping (but it is not), and softly and very slowly shifts into second. After about a week or two it clears up. If you disconnect the battery and reset the computer it goes back to acting up.

This has been true for several months. The other day I cleaned the egr plenum because it was stopped up ( got a cel). I d/c the battery to clear the code. It has went back to shifting odd now and won't clear up. The car now throws a code saying the egr sensor is faulty. But the engine runs smooth, has plenty of power. Just the shifting issue.

Any ideas?
December 2, 2011.

Have the computer re-scanned for code/s sounds like the transmission is slipping-How's the fluid level and condition. If okay bring it in and have it pressure tested-

Dec 2, 2011.
The only code it gives is Egr sensor faulty. I cleaned the plenum because it was stopped up giving EGR Flow error. The engine operates normal and has no power loss or pinging.

Other than that, no code. I changed the fluid about 10,000 miles ago and filter. I checked it to make sure it was full.

Dec 2, 2011.