1997 dodge ram 1500, 5.9. I keep getting code p305 for a cylinder 5 misfire. Put in a new oxygen sensor the other day, but I think it threads are slightly stripped on it. Can this cause the misfire again? I've got new wires, ngk v power plugs, accel cap and rotor, and I hear a ticking sound coming from the #5 injector. Any thoughts?

 

When you unplug the O2 sensor does the misfire disappear? If not, the problem is not in the O2 sensor (plus an O2 related misfire should not do so on a certain cylinder all the time).

Check the actual wire that powers the injector, maybe its a bit loose/broken. Make sure the spark plug gap is proper.

 

Since you have 204 posts have you done either one of these things? http://dodgeram.info/tsb/1998/18-48-98/18-48-98-v8.htm and this http://dodgeram.info/tsb/2000/09-05-00.htm

 

after that...
O2 won't cause misfire in a single cylinder.
check for spark on spark plug #5.
inspect spark plug #5 for abnormal appearance.
do a compression check.
if this is all normal, consider swapping injector #5 with another cylinder.

 

I've already routed my wires to spec per that tsb and I've done the plenum with a steel gasket 4 months ago. Has Ngk v power's gapped at 0.35. I know I'm getting spark thru #5 wire also. I got me an injector today at the junkyard. time to swap it out and see the results.

 

I'd swap one of yours from that rail(as stated above) before I put one in from a JY that might be bad too. God only knows how long the JY injector has been sitting.

 

I heard that, but I already swapped an injector from an old one that I've had. Now after putting the junkyard injector in, It runs about the same. I've paid attention to it over the last few days and noticed a few things. 1; under heavy/WOT I'll get the p305 code and a fouled spark plug. 2. truck will run rich and rough after getting gas/cold start and within yards after pulling away from the gas pump with throw the cel for p305. This makes me think it's fuel related and not in the spark. Last night I drove it about 50 miles and came home and parked. Went inside and then came back out to move the truck in the driveway and when I cranked it up it was POURING white smoke out of the exhaust and smelled like it was running way too rich. I've replaced both oxygen sensors with brand new bosch ones within the last 5 months.

 

Bosch o2's are junk and white smoke usually means cracked head or blown head gasket. And what does "I've done the plenum with a steel gasket" mean?

 

Took out the mildly blown stock rubber plenum gasket and replaced it with a new steel embedded fel-pro gasket and put thicker washers on the new plenum bolts. That was the plenum problem right? With the bolts not bottoming out?

 

The bolts are a small part of the problem! The plate is the main problem. I'm not saying the gasket is blown again, but since you have 209 posts, are you not aware of all the facts about the plenum?