beefbusta

hey all, I just installed a Vibrant Header/DP combo and hooked it up to my GMPP performance cat back, the car now runs like complete ****. I don't have a wideband but by looking at my exhaust it looks like i'm running extremely rich. whats happening is the car is idling at about 900 RPM, and if i give it the slightest amount of gas, it acts like it wants to stall, and it also sounds kinda like an exhaust leak as there is a slight rasp (lol sounds like a friggn lawnmower), but i cant detect where from. a few of the people that helped me install it say it needs a tune and they swear there is no leak, but i did some research and i never saw anyone else have to get a tune after only having Intake/Header/Exhaust... but maybe i'm wrong. your thoughts? thanks in advance.

also, according to another thread posted on here, it says that we should torque the bolts at 106 in/lb to the manifold (those 10 bolts if yall know what im talking about).. the dude that was helping me said thats extremely low and that could also be part of my problem thus causing a leak.. anyone know what it should be at?

terry11

iTrader: (6)

Use a multilayered gasket. I just tighten them to where they feel tight using a standard size wrench or 1/4 inch drive rachet. Is your leak from the back of the head or the downpipe?

ls1fbody

106 is pretty damn tight haha. Your lugnuts are only 90...

BLAZIN07SS

iTrader: (7)

in/lb, not ft/lb sir

blackbolt89

inch pounds is different from ft/lbs...

106 in/lb is like ~9 ft/lb

iirc the reason why its so low is because if you really try to crank on a bolt into an aluminum motor youll strip out the threads.

i could be wrong on everything i just posted. im just sayin

SprChrg4Life

iTrader: (1)

hang on, hang on... you wanna avoid an exhaust leak? I highly recommend you torque your header down properly. check out the header and downpipe how-to in this link.:

https://www.cobaltss.net/forums/how-guide-43/how-install-header-downpipe-158475/

Go down a few pics til you see an AllData picture in black and white that has the 10 numbered bolts on it, torque down in that sequence and follow the instructions above the pic

then just go back and check your header to downpipe bolts, as well as your downpipe to catback bolts. oh and make sure your O2 sensors are plugged in!! a leak is what you hear... also, you may have damaged an O2 sensor wire, grounding it out slightly and confusing the computer.

essentially, check O2 wires, the condition of your O2 sensor, your nut torque (and do it in the right sequence!) as well as make sure they are even plugged in. report back

beefbusta

Thanks for all the feedback guys. I actually followed directions exactly in that how to thread including the order of bolting in.. What's really wierd is the first time I started it up and drove it home it ran like ass. Then I saw there was some dude with a camaro that had the same problem. He said to resolve the issue he turned his car off then turned it back on. I said bullshit, but I tried it anyway. The car now runs fine lol but still apparently had a leak as it sounds something like a lawnmower as I try to accelerate, that and I'm only getting 10 lbs of boost which I'm assuming is also cause of a leak due to back pressure.. So to resolve this i'm probably just gonna go pay some mom n pop shop to find and fix the leak cause that header install took forever lol. Is my assumption of lowered boost correct?

metalmedic

iTrader: (4)

i put a vibrant full exhaust on and i was runnin like ****!!!! but come to find out the o2 sensor grounded out and my maf sensor was bad.. and i did have to get a tune my car was runnin really lean... alot of carbon deposit (black cloud comein out the tail pipe when u get on it)... but ya kinda off topic does anyone know if its true that on a vibrant header down pipe that port 1 o2 sensor only runs off 2 cylinders???

beefbusta

that would be news to me.. question for you though, did you have to get a new exhaust manifold gasket? mine didnt come with one and autozone, o'riellys, pepboys, and napa don't sell the gasket. I guess i'll have to go to the dealership to get it. But now im driving around with a nasty leak and it sounds somewhere between a fart and a lawnmower. ew.

DSmastery

iTrader: (5)

i have full vibrant header/ dp and 3in cat back
i had a leak at the header to the manifold about a week after install, tighten it back up and the sound of like a propeller plane was gone haha
but have a tiny leak some where in the exhaust, but it doesnt make the car drive like crap or sound bad.

at low rmps 3k and lower its beast sounding, above that its some rasp(loud race car)haha as its a 4 banger
if the car was turbo well it would sound super bomb at any rpm

beefbusta

ROFL yea that perfectly describes it. A propeller plane is exactly the sound it's making. But your right aside from that it really doesn't sound that bad, just hard to pass judgement when your car sounds like it's about to take off for flight.