I have a 2000 Jeep Grand Cherokee Limited 4.7 4wd that I've been working on. It gave me a 132 and 138 code so I changed the sensors. Still gave me the codes after resetting. After doing some research I changed the AIC and TPS. Still throwing codes and rough idling. Help! Not sure what the next step is.

 

These codes indicate "O2 Sensor Shorted To Voltage" and "Oxygen sensor input voltage maintained above normal operating range." It's too bad you shot-gunned the sensors. That's the kind of logic that makes people think Jeeps are too expensive to maintain. Your best ally in keeping a Jeep is what we like to call the "K.I.S.S." principle (Keep It Stupid Simple) and to always abide the basics first - before throwing dollars at it.

If you had only one of the two codes then I would be more inclined to replace a bad sensor. Still I would do a basic checkout first but, in your case, because both are reporting my first suspicion would be that of a bad ground (G104) and/or wire-splice (S104). Both in the engine compartment. See the 2000 WJ Factory Service Manual, Wiring Diagrams, Ground Distribution section, page 8W-15-3. If you don't have a manual then you can get one on-line for only $8 from www.pacificcoastmanuals.com. It is a small investment to save yourself thousands of dollars in the long run. If you plan to keep and service your Jeep then you'll be glad you got it.

First, to get familiar with it, look-up the locations for the engine compartment grounds at G100, G101, G102, G103 and G104. It'll be a good exercise to do them all but, more specifically to your situation, seek-out G104 and S104. Both of these 02 sensors have a spliced connection at S104 in the harness and I think that's where your problem lives. Grab the necessary tools, devote an hour to getting dirty and/or get technical help which is always recommended.

Disconnect your battery at the negative post and tape-off or move the cable terminal away from the post so it cannot make accidental contact while you are working. Use penetrating oil (WD-40 will work) first on each of those attachments found at a body/chassis location and let it soak-in, then unbolt and wire brush every one of them until shiny, repair or replace any bad or broken wires/crimps/lugs. After re-attaching, give them a coating of dielectric grease. While you may not need to do all of them this time, your Jeep will thank you in reliability dividends if you just do them all in one round.

 

Along the same lines as what Cherryokee says, if you have any corrosion on the battery cables, make up a paste of baking soda and water and using an old toothbrush, scrub the battery terminals with it. when it stops bubbling, flush with water and do it again until it doesn't. Corrosion in the wire to the relay/fuse box under the hood can cause a voltage drop and cause all kinds of weird stuff to happen. If you have a battery with vent caps, clean the top of the battery case as well. Acid vapors can condense on top and cause a leakage path which causes the corrosion.

 

I ended up taking the Jeep into my regular mechanic who admitted he hadn't worked on jeeos before. He told me that there are connectors for 4 02 sensors. However this is not a California emissions vehicle so I told him there are only 2 02 sensors. Who's right? He won't even diagnose the vehicle because he thinks someone swapped out my exhaust and out the wrong one in because it only has 2 02s. Thoughts?

 

I will try that and hope it clears up the code and rough idlling.