My question is this: How important is the Knock module in a OBDI computer, and what happens to the car when It is removed?

So here is the story; I bought the car from my friend and a few years ago he took it to a GM dealer to run a diagnostics on the car. I remeber him paying about $80 for it too! Well I bought a computer from a friend and installed it today. The new computer had it tuned for a gears, cold air intake, Long tube headers and the AIR and EGR romoved. All of which is what I have done to my car so far. Well when I was swaping in the new computer, the old one which I thought a had a LT4 knock module in it, since I was the one who installed it for my friend some time before he brought it to a stealer, only to find out it had been removed! Now What would that do to the performance of my car having no knock module at all (LT1 or LT4) in it? I took it to the track this past weekend and ran some really sad times, sad enough where I would almost rather race my ZR2 instead or cry!

 

man that might have an impact on what the computer sets timing at for sure.

I dont know all there is about the OBD1, but it would seem that if it didnt get a reading it would be throwing a code or retarding by default.

 

Well it hasn't thrown any codes that stay on for longer than a minute after I just installed a new MSD Pro Billet opit, plugs and wires, OR LT Headers & Y with a cut-out. Befroe with the opit that was WAAAY beyond shot it never threw any codes. But after all the work I did I couldn't pull more than .4 sec off my quater mi times when the car misfired and ran likte complete ****! Not to mention I get at best 14,5 mpgs! It sucks! Makes me really pissed... well enough venting

 

It has NO KM, or just the factory LT1 KM? If it's the stock LT1 KM, don't panic.

 

Just buy a LT4 KM or even a LT1 KM and put it in, and be done with it. Just monitor your results.

Dont worry I am getting 13.9 MPG right now. (tracing that prob)

 

Werent you putting a cam in that thing?

I recently dynotuned my car and it made good numbers N/A. However, if i open the cut outs, or am just cruising around town it sets off the knock module and immediately retards the timing like 12-14 deg, but when im on it it goes, and goes good..

I am buying an LT4 KM this week from www.gmpartsdirect.com

$52.00 shipped..

 

I opened up my computer and there wasn't even an KM in it! It does run better now that there is one in it... I'm hoping the MPGs will get a little better now

 

Well even if you get a tune they say a LT4 KM is a better filter than the stock anyways.

 

Well I have an LT1 in it for right now, but I will be hopefully getting an LT4 in the next few days.

 

Yeah if you gonna cam or make you car louder, it is a good upgrade to reduce BS false knock.

If you get a scanmaster or datalog program you can monitor these things, and take the guesswork out. I am almost sure that you were getting max or close knockretard with no module. I know they can program or desensitize the actual knock sensor that is in the block, but that is more extreme.

 

Now I'm not sure about the module its self, but having the knock sensor unhooked adds 9/10 of et and drops 7 mph on my car. I don't feel like typing enough to explain exactly how I know this, but it was on back to back passes, with no other changes.

 

That's because unhooking the knock sensor will set a DTC that will pull a huge amount of timing. If you want to delete the knock sensor you have to tune it out in addition to unhooking it.

 

The OP was asking how much performance he might be losing, since his car didn't have a knock module in place. I simply informed him how much my car lost on one pass from not having the knock sensor hooked up, because I thought it might be relavant to his question. I'm well aware of what caused the decreased performance.

FYI, With a little research the knock sensor can be bypassed without touching the tune and it won't pull timing.

 

That was pretty much my question guys, I was running horrible times at the track. I ran 3 passes on a 70 degree day with low humidity and I could only best a 14.7 at 93. That was really dissapointing after all the work I did to it. So if it should gain 9/10ths of a second then I will be right where I should be, 13.8 or 13.9. And then as I said before, I hope my gas mileage improves too.

 

cool, I was just providing additional info, wasn't trying to call you dumb or anything