1999 k 1500 truck running rough

[solid 12]

A buddy of mine has replaced his plugs, wires and o2 sensor on his vortec 350..it still runs rough and throughs a miss fire in cylinder #5 and o2 code..any ideas of what could be wrong?? Just tryn to help a buddy out

Thanks

[RIP_K52007]

Kind of a older problem but worth a shot... coolant temp sensor.

[solid 12]

Ok, i will let him know.  Thanks!

[RIP_K52007]

I'll ask my neighbor tomorrow he has a 2000 that pulled the same stuff I think. I don't remember what fixed it though.

[solid 12]

Ok, thank you

[betterbeaters]

put a 540 in it?  lmao check the cap and rotor too?

[xjs3667]

what plugs did he put in?   GM engines run best on AC plugs, replace them with what came in it.  Everyone I know that puts somethin other than ac plugs in, always ends up with a missfire

[solid 12]

I will ask him what were put in..thx

[Strapless]

Worn distributor gear is very common on them also.

[ProGrade]

Worn distributor gear is very common on them also.

x2

[solid 12]

Ok, thanks for the input