ptep121

Recently replaced pre-cat o2 sensor. CEL was on before i replaced it, went away as soon as the new part was in. Still getting a bogging down at idle or low rpms like I was before. Plugs replaced 7500 miles ago, wires/cap replaced 3 months ago, after-cat o2 sensor 2 months ago. Just posted about bogging down at low rpms here (https://www.cherokeeforum.com/f2/new...h-idle-126606/)

But then as I was driving home today things got worse... the Check Gauges light came on (first i've ever seen that one), the battery gauge was all the way to the right, and the radio kept cutting out for a split second then coming back on again. Also noticed the oil pressure dropping at idle then increasing again while driving (much moreso than i've ever noticed before).

The Check Gauges light was only on for about 5-10 minutes then went away for the last half of the drive. Is she possessed??? Do I need a oil sending unit or an exorcist??

freegdr

sounds like connection issue some where, grounds been checked

DFlintstone

Maybe the key trick might help find it? ^

Newer (OBDII) models - Put the key into the ignition, push down the odometer reset button, then turn the key to RUN with your finger on the button - and then release the button. The odometer will go through 1111111 through 999999, then display the car's serial number. It will then show the error codes (it might show them starting with P). If this method does not work, try the OBDI method.

tjwalker

The above symptoms combined really sound like a systemic electrical problem. First thing I would do if this were my vehicle would be to "freshen" all engine grounds. like freegdr mentioned.

Gotta rule grounds in or out early in the troubleshooting process. More on that below. Good luck and keep us updated!
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Grounds can be the root cause of many electrical gremlins. Refreshing grounds is NEVER a bad idea, and the investment of your time in this procedure is always well worth it!

You can't tell much of anything by looking at ground connections!! You must remove, scrape, clean until shiny the cable/wire ends and whatever they bolt to. Be sure to remove all paint from any ground connections.

Start with the one on the back corner of the head, and where it attaches to the firewall, as it deteriorates over time and is an area that makes it susceptible to damage. Best to replace that woven cable with a #4 or #2 gauge cable. You can attach the one end to the intake manifold if you would like.

Next go over to the engine dipstick tube stud. Remove the nut and clean the wire ends and scrape the block until shiny at the stud. Reattach tightly.

If you are so inclined, add at least a #6 cable from the negative terminal of your battery to one of the bolts on your radiator support.

ptep121

Thanks for the feedback! I'll check the grounds and follow the specifics you posted.

Check Gauge light came back on as I was driving to Auto Zone last night, but when we went out to read the codes it went away... Curious to see what that code said.

tjwalker

A "check gauge" light will not set a code.

A "check engine" light will.