It'* possible the VSS reluctor wheel is gummed up. I would say remove the sensor and look in the hole with a flashlight. You should be able to see the wheel. Here'* what it looks like with the diff cover off. It'* the gear on the end. Each tooth should be clean.

cool. thanks. i'll check that out as soon as i get the car back.

i got it back and the shop says all the electronics are good. it must be the reluctor wheel. does anyone know if the air gap would have anything to do with it? i haven't had a chance to check if it was gummed up or anything, but the shop said they checked it out and couldn't find anything wrong with it. it wasn't loose, not shifted, no teeth missing. i dunno what else to look for.

I really don't see a gummed reluctor wheel doing this, or an 04 having any. Was the VSS sensor an OEM AC Delco? Did the shop check to see if it isn't defective?

There is no way to adjust the gap between the sensor and the wheel. If it was me checking this, I would have my oscilloscope on that sensor. Possible causes are, bad reluctor wheel, bad sensor, bad sensor plug, bad sensor wires, problem in PCM. You have changed the sensor correct? You need to start removing what works, and the list will get smaller, until all that is left is what wrong. Start at the sensor and have the shop test with a oscilloscope. If the wave form looks good, then test the sensor again at the other end of the wires. Another possibility is your spark plug wires are laying on the wiring harness. Make sure the plug wires are not touching other wires.

Dan your putting alot of 3800 retrospect into this. We don't have spark plug wires.

Scratch that part then. See, the list is already shorter.

LOL, and the shop says the reluctor and wiring good. Really wondering if he got a bum sensor. It happens.

DOA is always possible. That'* why I suggest testing the wave form. This will say without doubt, if the sensor is good or bad.

well they tested it with another sensor and got the same voltage output. i got another sensor and it still did the same thing. they checked the reluctor wheel, the wiring, i changed the connector, and everything else looks and checks out fine. i think i'll have to take it to the... dealership. don't really wanna take it to them to hear some bullcrap, but sounds like i may have to.