Driveshaft screw-up causes rough idle?

Spent the day wheeling Sunday, everything is great.

A couple miles after getting off the trail, the rear drive shaft lets go at the transfer case (I didn't put locktite on the bolt holding the yoke on my hack-n-tap :doh

Drive shaft smacks the jeep a couple times. I see the oxygen sensor wires are smashed and cat has a couple dents in it.

Pull off the drive shaft and immediately notice rough running until it hits 1500 rpm. As long as I keep it above 1500, it's smooth.

I replaced O2 sensor. No change.

So, is the rough idle caused by something the driveshaft hit or is it just coincidence? (2000, 4.0, auto, 231)

Haven't yet replaced rear driveshaft, but I don't think that would have anything to do with it.

Any ideas?

Thanks!

Steve in Colorado Springs

you may have torn the O2 wire

I replaced the O2 sensor. No change. The damaged portion of the wire was replaced with the sensor.

I'm saying you might have torn it further up

ehall said:

I'm saying you might have torn it further up

Click to expand...

Definitely. When the DS impacted the wiring it could have stressed the harness quite a ways up stream. Check it with a meter for continuity/resistance.

Also, how bad is the CAT? The honeycomb really doesn't like to be hit.

This is my cat. No major dents, but obviously got smacked a few times. Think it's too far gone? Is there a way to tell if it's bad?

As for the O2 wiring, there's about 6" of slack on the vehicle side of the plug. There is not indication on the wiring itself that it was hit and the plug was still up out of the way and hadn't been pulled down. Don't see that the wiring on the other side of the plug would have been damaged.

Is there a sensor or other component that only affects the engine up to 1500rpm? As soon as it hits 1500 rpm it gets smooth instantly, like something is switched on or off at that point.

try disconnecting sensors and see what doesn't cause a change

I think I'm making some progress. Got a check engine light today and the code is P0443.

Anybody know what it is? I see a couple posts, but no idea what to do about it.

Is this related to my driveshaft misshap or just coincidence that it happened at the same time?

Thanks for your help.

Steve in Colorado Springs.

2000, 4.0

check your lines running along the drivers side frame rail for damage.

P0443, EVAP purge solenoid circuit, open or short.

The EVAP system captures fuel tank vapors and meters them into the intake manifold to reduce pollution. You would have lines running from the tank to the canister on the firewall. They might very well have been damaged by a free range DS.