Check Engine Light

The check engine light just came on in my 2001 XJ with 5.5 lift and 33s. After i was done testing out some new stuff on the rocks and got about half way home my oil preasure dropped to about 20 when it normally runs at 40, then the check engine light came on. Any ideas of why it happened or how to fix it?

best bet is run to auto zone or any place that will give you a read out of the error code you are getting. That will help a lot with that light.

cycle the key 3 times in i think it's within 7 secs or so. (procedure should be in the owners manual) the odometer will display the error code. then either hit the library, go to a parts store, check the web, post the code here, buy a manual or get a code reader.
Typically, the computer will not set an error code on the first hit. It takes several cycles in order for the computer to set a flag. I doubt the oil pressure dropping and the check engine light at the same time are directly related.
Case in point, when I reinstalled my tcase, the speed sensor was clocked one off resulting in no speedometer movement. It took the computer about 10 miles of driving to acknowledge that there was no vehicle speed sensor input and tripped the check engine light.

DaffyXJ said:

cycle the key 3 times in i think it's within 7 secs or so. (procedure should be in the owners manual) the odometer will display the error code. then either hit the library, go to a parts store, check the web, post the code here, buy a manual or get a code reader.
Typically, the computer will not set an error code on the first hit. It takes several cycles in order for the computer to set a flag. I doubt the oil pressure dropping and the check engine light at the same time are directly related.

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Unfortunately that trick doesn't work on OBDII (98+)you need to get a scanner or have it scanned.