O2 sensor?

[byrinxx74]

Ok so i have been having a idle problem. It would just shake. So i have changed everything, wires,spark plugs, cap, rotor, fuel filter, iac, tps, cleaned throttle body. I hooked it to a scanner and is was showing the upper exhasut going from lean to rich to center. My question is, is that telling me that the o2 sensor can be going bad because of the flux and would that cause a shake at idle.

[seu83]

Very possible. An upstream o2 could easily cause a rough idle. What is it idling at? Almost sounds like it's idling really low or has a mis.

[4.3LXJ]

How fast is that cycle?

[byrinxx74]

The cycle is pretty fast. Enough for me to stop to notice that this mite not be right? The idle is at 750. Its normal, the rpms do not move at idle, its just the vehicle it self and motor.

[4.3LXJ]

There might be two issues here. First if you haven't replaced that O2 sensor in forever, it should be changed anyway. The second issue might be dirty injectors. If it is cycling fast enough to coincide with the engine speed, then that might be most of the cause. Put some Sea Foam in the gas tank and just drive it. That will help clean the injectors and take care of any carbon in the cylinders too.

[byrinxx74]

I have tried that, i put seafoam in the tank, and throttle body. I also cleaned the throttle body as well. I have put a new fuel filter in, spark plugs,wires,cap,rotor. Im at a loss of what else it can be. The compression is 172 in all the cylnders so i know thats not it. There are no codes, and the jeep passed smog about three weeks ago. Its the weirdest thing ever. Drives good, its just at a idle it seems to shake then try to correct its self.

[4.3LXJ]

Your idle air control is probably just a little sticky. That is not a bad fluctuation.

[byrinxx74]

Yeah mine does not hav a idle flux. It just shakes to we're u can feel it onthe steering whel and ur butt.

[Ryan96xj]

my 96 is doing the same thing