Mattsz28

iTrader: (1)

I recently installed a set of Grot headers on my 95z. My butt-o-meter was telling me that the car was faster than it was before. I was first able to take it to the track this friday and the car ran almost .4 tenths slower than it did the week before the header install. The only thing I could think of that could cause this kind of problem is that the computer is picking up false knock. The plugs are new, the wires are new, nothing is burnt or arching. I have not yet got a chance to hook it up to my scanner to see how much timing is being pulled. So the real quesiton is, if this is the problem, will an LT4 knock module fix the issue? Can I just pick one up at a GM parts counter? Does anyone know the part no, I tried a search and came up empty. I would order it online, but I dont feel like waiting for it . Also, I had the computer tuned for the "knock desensitizing" feature, along with the headers. Would this rule out the knock retard? The headers arnt leaking at all as far as I can tell, and even if they were, would that cause almost a half second of lost time?

Built LT1

iTrader: (3)

Getting the knock module will help but not eliminate the problem. You can tune the computer to not pull out timing if your sure it won't detonate. Just use caution. The knock module is around $25 and a dealer should get one quickly.

C_Rules

iTrader: (7)

well i have knock and got an LT4 km and that didn't help. Try a datalooger and some race gas to see if you have real knock or not. If you put in a couple of gallons of race gas and still have knock then its false knock. If it goes away then its probably real and you have a serious issue. Also go over the underside of your car to make sure you dont have anything rubbing, hitting, or clanking. Im trying to fix the knock on without tuning first. If that doesn't work then i'll desensitize it as long as its false knock.

GreatWhiteZ28

iTrader: (15)

about 99% of the guys on here are running a LT4 KM to help out iwht the false knock crap on out cars, I have one, it helped alot but it still picks a false knock, (depending on how hard I launch) I picked mine up from O'Reileys actually but yes the GM parts counter should have on hand as well, the AC-Delco # is 216-67 GM # is 16214681

Mattsz28

iTrader: (1)

Thanks for the help and the ideas. I highly doubt the motor is actually detonating on premium, the only thing it has done (internally) to it is a hotcam kit. I dont think the header install would cause detonation. I have heard that it can cause you to run extremely rich, but I had the car tuned for the headers, so I thought that this would be a non issue. I will get out of work a little early (!boss! mod) and try to find the knock module. I will also go back over the Y pipe and everything else. If that is "knocking", will that cause my issue? I already went over it once, but I thought I heard it this morning on the way to work again. I am sure we have all done something to a car that we thought would boost performance only to have it hurt it. It was compeltely disappointing. Hopefully I can get this issue cleared up, so I dont have to spray her to pieces

Captainofiron

iTrader: (1)

you also have to remember the stock manifolds are cast iron, a property of which is to reduce and absorb vibrations, with the steel headers the vibrations of the exhaust pulses could be picked up as false knock, my car was doing this also when I first got LTs, the LT4 KM helped me though. I do need a tune, but in the mean while this helped fix it

FAD2BLK93

LT4 knock module gm #16214681 list price 69.78.