Once again, after my header install I'm having more problems. Rough starts, leaks and not quite the performance gains I expected... Heres the deal, after I had my headers and exhaust installed, my car started kinda rough. It only got worse until I got around to putting a new starter in. That helped, but not too much. I still have the stock plug wires on as well. Also, I noticed when I got it back from the shop that there was oil all over the place in the underbody. I wiped it up when I put the starter in. Well, now its dripping again. Also, I went on a highway trip and it seemed fine on the way up, but then it started up really rough when I was heading back home, also, it began whistling like I had a supercharger or something (could of been my fans but it just seemed strange since it didn't happen before). Also, my gains in performance aren't quite what I was sure they would be. My brothers stock LS1 seems to be just as fast, if not, faster than mine with all the mods in my sig. Maybe my speedo is off or something. I don't know but it just seems like something is kind of holding it back. Any help on any of the issues above would be greatly appreciated. I just want my car running smooth again. Thanks.

 

Get that car scanned and have a look at your logs. It may be detecting knock or false knock retarding timing.
Change those stock wires! If theyre 11 yrs old you'll notice a huge difference. Check to make sure your intake is all on right and that you don't have any tears. The car shouldn't whistle, the only time my car does anything close to whistling is when the engine is cold and the AIR pump kicks in.

 

Maybe you are hearing an exhaust leak?

Your mods in sig dont say dick about a cat back exhaust. If your running stock muffler and I pipe, that WILL choke up the exhaust. Also, with your mods, you should be right around a stock LS1, not significantly faster by any means.

Really, you should change your plugs and wires now. Also, the car may be running like dick if you have coated headers. Stuff burns off on the inside, and clogs up the O2 sensors. Clogged O2's dont respond as fast and the car will run ****ty. Check your O2 readings. They should constantly fluctuate between 100-900mV.

 

make sure the oil dipstick is all the way in to, you could have wiggled it loose during the install, that could cause a oil leak, also make sure the wires are all in good cond. ie, that there not melting or burnt from being too close or on one of the primaries.

 

The whistling sound is a vacuum leak. That will cause it to be hard to start and idle bad and be a little short on power. Check all the hose connection.

 

I thought maybe the whistling was an exhaust leak as well. I don't know yet but I'll find out. With my cat back, it's the SLP Loudmouth, no cats or muffler, it's practically straight pipes. And yes, I have the coated headers.

I guess I'll have my car checked out, get new O2's, plug wires, and check for vaccum leaks or leaks anywhere else. I know I at least have an oil leak somewhere because my underbody is dripping with oil.

BTW should I just take my car to my shop and have them scan everything and check O2 readings and stuff? I'll do whatever I can on my own, but I've never had to deal with any of the stuff mentioned above.