O2 snesor shorting out only cylinder #6? Can that be?
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O2 snesor shorting out only cylinder #6? Can that be?
This is my third posting on the continuing saga of a misfire developing after rebuilding my transmission on a 1999 Dodge Ram 1500. After a new crank sensor, timing chain, cat, upstream O2 sensor, fuel sync, distributor, rotor, wires, plugs and swapping injectors I was about ready to replace the PCM. I posted about a NOID lite not puslating, staying on and began checking for a short. #6 was the only injector not pulsing. So I started at the PCM. 5v wire goes to #12 spot of #2 PCM connector, ground to #12 of 3rd connector. I found if I unplug the #3 connector I would get a short registered from my DVOM. If I left # 2 and 3 connector plugged in and removed #1 the short went away. If I left #3 and #1 connector plugged in, no short. With #1 and #2 plugged in the short showed again. So I figured it wasn't the ground wire. I started pulling fuses and relays, one at a time and testing. When I got to a 15a fuse for the O2 sensor the short went away. I put the fuse back in unplugged the upstream O2 snesor and still a short. Plugged in the upstream and unplugged the downstream still a short. Unplugged both and no short. More wire to trace but why this is only affecting the #6 cylinder is a mystery to me. Anyone ever run into something like this?
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