ktmrider

Not totally sure on the KS numbering but someone should chime in. Being as cheap as they are I would personally replace BOTH while in there. Either that or ask someone at a local dealer, should not be secret info.
Reminder, check out www.LS1Tech.com under the "Intake Manifold Swap" section for F-Body how to's. It lays out all the parts, tools, and time that you should expect to need. It may be for cars but most/all of it is applicable to the truck motors ( gotta love GM for things like this ).
In addition look under the "LS1 to LS6 PCV Conversion" thread as it shows how to remove the KS specifically.

nonnieselman

iTrader: (10)

ok i changed both knock sensors out fri night, it only took me 4 hours! i about lost it! i cant believe how hard then stupid connectors are to get off. so i just broke the top of the old knock sensors and just pulled the connector out and cleaned it up. i know why the knock sensor in between #5,6,7,8 was out or messed up. i got 3 of them blue shop towels, and soaked up the water out of that hole. so when i got through and double checked all the bolts and connectors and checkd them again. i unhooked the battery while we were cleaning up all the tools and stuff. i went to crank it and it didnt want to idle worth a crap, the SES light was still on. so i unhooked the battery again. and same thing it would idle it would try to idle at bout 500-600 then drop to 100-200 and then come back up, it would rev up good and i could hold it steady at 2k and 3k and it didnt hickup or anything. i finally got tired of it and went and opend it up a few times on the road. when i got back i checked the bolts on the intake, unhooked the battery again. when i cranked it, it ran fine, idled better than it did. but it is still kindof rough idle... i dont know what to do!?!?

ktmrider

Glad the work went fairly well. BTW, there was a TB out on using some RTV to seal off the intake area for problems just like yours ( the taller truck intake has foam at the front and rear that can break down and not seal ).
Sounds like an air leak to me. The old school way is to spray starter fluid around the intake gasket and see if the idle changes. Did you replace the intake gaskets?!? Just checking....

nonnieselman

iTrader: (10)

no i didnt change the gasket. i bet that would be my problem. but it has never idled smooth as i though it would. i got in my boss 04 avalanche 5.3 and his is just a little smoother so im not goin to worry bout it

nonnieselman

iTrader: (10)

i noticed in my bosses 2500hd w/8.1. it idles really rough. he is running 87oct. i put the 89oct tune off hypertech on it for him. he said 93 was killing him when he filled up. 9.5-10 mpg average. that hurts to even think about it!!. i did notice when the motor is cold in the morning it dont want to idle right. its hard to explain but is almost sounds like its missing on one cyl. so i just get in it and start driving. im ordered ProScan wed. so i hope it might help me out??!!!?