Would bad terminals really cause these issues? I guess it makes since; bad connection means bad reading from the volt gauge. Low reading would trip the CEL. Ok, I guess I will go ahead and replace these. Otherwise, Autozone is my next stop this morning.

Btw, where is the sender for the volt gauge?

 

How old is your battery?

 

Only 2-3 weeks old. Just recently bought it brand new from A/Z.

 

So I just did some more research, and one of the codes Im getting signals an alt. field control circuit open or shorted. This is Code 41. What sucks is that upon further research, I found that this issue usually means a new alternator is in order. Anyone have some confirmation with this?

 

When you first start your jeep - CEL light is on and low volts on gauge - Crawl underneath and tap on the alternator, If it takes off charging and CEL goes off plan on a new alternator. Mine has acted that way twice and having it checked was a waste of my time since it would never show a problem while being tested!!!!

 

Also, code 21 is (Oxygen sensor signal out of range, possibly shorted). Would my alt issue cause this to pop up? Also, if it's any help, I was really low on gas the day before I got the code. Like, I was on E, and when I filled up I had only had maybe 1-2 gallons left in the tank. Would this be a relay or something that could need replaced?

 

With an intermittent charge anything might pop up! Not likely to be related, but old parts are susceptible to oxidation and corrosion. Check to make sure the wiring for oxygen sensor has not melted on the header.

 

Ok. Also, I read somewhere that an O2 sensor can give a false reading if there is an exhaust or intake leak somewhere. I have a pretty noticable exhaust leak from my cracked header (if sitting in one spot idling, you can start to smell it). Would this trip my O2 sensor?

 

The potential for a bad reading is there, but mine has been cracked for over a year and has never triggered a code. It's not a big crack, but if it was then maybe i would be telling you otherwise.

 

Actually, nevermind the o2 code. I just went outside and did the key trick again, and the only codes she gave me were 12 and 41. The 12 is in response to the disconnect I did last night to clean the battery posts and terminals, and the 41 is probably the alt.

But thank God, that O2 code is gone. One less thing to worry me.

 

UPDATE!!

So, I went and started my Jeep and had the same CEL, except this time the volt gauge went straight up to 14 volts like it should. Went to A/Z and had the system checked. Checked battery, it was fine. Went to start the Jeep for the alt test, and no CEL! No alt issues, and the test said it was doin fine. I guess the ECU fixed the open circuit insted of throwing a code 47 or 46. Plus, I think the Jeep was just mad at me for leaving her at the Shell station just below our house because I thought I was about to run out of gas. What can I say; Jeeps have minds of their own.