I have a check engine light and was wondering if it could be caused by a knock sensor ? since I have a header leak I am suspecting that this is the prob.

any thoughts or answers?

 

It would definately do something to the computer, pull timing or what not, but the check engine light could be from something else, have you reprogrammed the computer using a handheld programmer? My parents had an 01 SS and it had had it's computer reprogrammed by the previous owner, we ended up having the somputer replaced because they replaced everything else, it also had somewhat of a header leak off of its hooker shorties. Knock sensor's aren't really expensive, so if you haven't reprogrammed your computer, maybe it's faulty, i do suggest doing something about the header leak. Good luck

 

it has been programmed by hpp3 in the past and now has a pcm for less program in it, i was told the exact same thing that you wrote by the garage that scanned my car and couldn't find the problem so I got another pcm and installed it and the light was still there, he also mentioned that the knock sensor code did come up on the scan.

any other Ideas??

 

your best bet would be to replace the header gasket, which i'm sure will be great fun for you. The gasket should set u back no more than $40,but the labor involved would cost a lot at a garage, so do it yourself! We had the computer replaced under warranty. so like i said, your best bet is to replace the header gasket if that doesn't help, replace the sensor, if that doesn't fix it, you have a bigger problem somewhere else. Good luck

 

It'll throw a code, not sure if it will throw the SES light.

Code 43 - Knock sensor circuit.

 

I did replace the gasket this past weekend and I still have the light but I have heard some people have KM issues from just the headers with out any leaks because they are louder than manifolds.

 

it does not actually say " serice engine soon" it's just the light that looks like and engine . I think there are 2 lights 1"ses" and the other is the engine am I right?

 

DTC 43 does turn on the SES. Attempt to find your problem.

With the connector off the KS, check for 5v on the harness terminal with key ON. Continue if that is good. If not good, check at pin D22 on back of PCM.

Key OFF. Connector off. Measure the resistance between the KS terminal and ground. Resistance should be between 3300-4500 ohms. If it is not, the sensor is faulty or the sensor is not making good contact with the block.

If all that is good, it might be the knock module or faulty pcm.

 

Shoebox,
is there any way to check a pcm to see if it is faulty?? because I have my original and also another from a board member and I want to know if what I bought is good or faulty?

Thanks for the help.

Gary.

 

Only by process of elimination and ruling out all other factors.

 

O.K I will try what you suggested and see what comes of it,

Thanks for the help Guy's!! I really appriciate it!

 

We have a light that looks like an engine? I'm pretty sure the only "engine" light is the SES light. Where at on the dash is it located?

 

Maybe he's speaking of the "Check Gauges" light?

 

i remember a little picture of an engine with "service engine" under it, this was all one light.

 

I don't think the LT1 has any codes that indicate a problem with itself. The manual says to tap on it with a screwdriver or something to see if the engine sputters- checking for loose connections.

And the ses light rarely turns on unless there's a problem with emissions. My opti has gone to crap, one of my spark plugs wires got chewed through by a belt, and I can unplug fuel injector connectors without the light coming on. The ses light is almost worthless except possibly to make sure your emissions equipment is working properly. And even then it's not that great, parts could still be failing or working improperly, it's the reason they went to obd2.

When I had my 96 droptop though, the ses light would come on when I got some bad gas. There's definitely a large difference between obd1 and 2.