I found a line near the rear of the Jeep that apparently came loose from a T fitting above the rear axel. So far the check engine light hasnt come back on. Yee Haw, I hope that fixed it!
I have a 1999 wrangler sport 4.0 5 speed with an after market K and N intake. The check engine light came on and the dealer said it was the intake that caused it. He claims it is quite routine because of the massive inflow of air. I have checked several forums and have yet to see this mentioned...