i did my header installa coupleweeks ago and after it i've had a small problem. there are a few symptoms and they are...
*my rpm's at idle were right at or just below 1000 before the install, now it will go up and down anywhere between 600 and 1200.
*when i was at the track last night i couldnt get under like a 2.3 60'. i wasnt having traction problems, my car was bogging down really bad even when lauching from as high as 3000rpm's.
it would go down to a little above 1000 and then be fine but it was making me really mad. lol

it kinda seemed like a misfire at first but its MOSTLY only happening at idle and low rpm's.
i checked all the plug wires to make sure they weren't burnt.
i'm thinking it could be the 02 sensors but im not sure.
does anybody have any ideas as to what it could be??? cause i hate it when my car runs like s***.

btw, i did the race stylepacesetter LT's with the ORY with a magnaflow muffler dumped before the axle. my car has about 86000 miles.and has only had the SES light on for like 15 seconds, but i think it was because the elbow wasnt on all the way on the throttle body. its never come on since i put it back on good.

 

Did you change the knock sensor module after putting on headers? The LT1 knock module is sensitive to the metallic noise caused by headers, which results in the spark being retarded for no good reason. The fix for this is to change to a LT4 knock sensor module, which is not sensitive to header noises.

 

no i didnt.

http://www.gmpartsdirect.com/results.cfm

is this what i need??

 

The O2 sensors shouldn't go bad just because you put headers on, but you may want to recheck the wiring. You can also use a scanner to check the operation of the O2 sensors, and also look at the amount of spark retard being commanded. Also check for any codes that may or may not turn the MIL lite on.

 

pete is this a rare problem or is it common? I havent heard about anyone having their engine bog down after headers.

 

It is a known problem, and it dependson howwell the installation was done. If the headers rattle against the chassis or are not tight against the heads, the metallic noise gets picked up as spark knock and timing gets retarded for no good reason. Depending on how much the timing is pulled back, it could cause serious loss of power. However, it is a good idea to check the timing retard with a scanner to see if that is the case. It is always a good idea to scan the PCM when there are performance problems, and verify that all sensors send data that makes sense.

The LT4 knock sensor module goes for around $40 an is plugged into the PCM in place of the LT1 module.

 

well that makes sense then and it is most likely my problem. my y pipe was hitting my floor until i fixed it. thanks a lot for the quick answer!!

 

sweet thanks pete, now ill know what to do if i have that problem after i get my headers.

 

i am putting headers on my 2000 z28 this summer so after reading this now im wondering if i will also need that knock sensor mudule.. and is that what its called LT1 and LT4 module or is that just for the LT1 engines or is it called something else for LS1 engines?

 

The one of the LSX motors is going to be different, but I haven't heard of any issues with needing to replace it when doing headers, it's an LT1 problem mostly.