p0203 code, need help

I looked at the injector and the wires to it, i dont see anything obvious like a bad wire shorting out or broken. a bit more info for you guys, the jeep runs pretty rough at start up and idle till it warms, idling you can feel the motor skipping a bit like a misfire. when i get out on the road and get going it runs great, no mis and it seems fine other than it seems to be using ALOT of fuel or worse than normal fuel milage.

Year, engine, trans?
I looked up the code. Only a handful of things cause it:
Problems in the wiring for that injector (connector, shorts, opens)
PCM failure
Auto shutdown relay wiring fault
and, by far the most likely given that you also have fuel use issues,
the injector is stuck open.

98 classic, 4.0 auto. i put in another #3 injector, it was a stock injector from another 98 jeep, it is used but known to be good. so i got it all back together and reset the computer on my jeep and fired it up, at first it ran great then when backing out of my driveway it started sputtering again and just a little ways down the road my CEL came on again,, so i brought it back to the garage and gave up for the night.

With this code and with swapping in a known good injector, that pretty safely rules out the injector itself.

This problem is likely found somewhere from the injector connector through the wiring for that particular injector.

Will need a meter and start tracing it back.

Yep, if the injector is known to be good you are looking at bad wiring in the harness OR bad PCM.
You might try swapping another injector from the rail into position #3 just to see what happens. Unlikely to be any differnet but weird things happen - sometimes a "known good" injector just isn't.

Yup i just got it fixed and you guys were 100 percent correct, it had a shorted out wire, the harness was rubbing the rear of the fuel rail, it cut the loom and wore off the rubber on a wire, the #3 injector was grounded out. thanks for the help as you guys got me thru this one.

Nice easy fix. Glad we could help and that you got it resolved......

Cylinder 3 Misfire

This weekend, I started getting the same CEL P0203.
The engine would run very rough - it wasn't drivable!
Oddly, the CEL occurred when putting the Jeep in reverse.
I tracked it down to be the injector wire grounding out on the fuel rail.
I assume that the transmission/engine torquing differently in reverse was the culprit.
I repaired the wiring loom and secured it away from the fuel rail to prevent this in the future.

Never would I have guessed that this would happen to the exact same wire!

The fuel rail rubbed through the brittle conduit, and eventually my #3 injector wiring.


Yellow/White wire had a very small slice, exposing the bare wire.


Secured!