the check engine light is on in my car. it says that there are "multiple engine misfires" and also someting to the effect of "knock sensor, low voltage" it seems to have abit of a spark knock, but only at around 2g and only when it has a load on it but im not into it.

i was told that the spark plugs being improperly gapped or being old (my car has 112,000 miles on it) would throw off the knock sensor, i know i need to change my spark plugs but do you think that it is all thats wrong? i know where the knock sensors are at and i dont feel like taking off my intake unless nessecary. i plan on changing the plugs and then erasing the code and seeing what it does then.

also, would this effect the performance of my car much? i raced a 98 LS1 Z28 M6 tonight and he pulled about a car length on me almost the whole 1/4.

 

A tune up fixed my cars missfires. So yes, I think new plugs and wires would help.

 

By any chance, have you recently added headers? That's known to give false knock and cause the system to yank timing.

 

nah, the car is bone stock

 

Could be an 02 sensor

 

nope, it would have shown up in the codes

mulitple cylinder miss fires bank one
mulitple cylinder miss fires bank two
knock sensor low voltage
Cat below threshold bank one
Cat below threshold bank two

those are the only codes

 

So your pretty sure that is caused by 02 sensors? I am getting that code and had a feeling it was the 02 sensors because they looked pretty chared when I put in my headers.

 

the cats could be bad because of 112,000 miles but most likely because my timing is off. if it was the O2 sensor it would have told me in the codes