Not neon related... but general car help needed

Mr Josh Zombie · Post by **Mr Josh Zombie** » Fri Sep 19, 2008 11:35 pm

I figure this would be the same diagnosis on any car so here's my issue:

Small background on my car.

-2006 SS/SC 24,xxx miles
-Megan cat-back. Been on the car for roughly 1,500 miles.
-WOT box. 2-step has only been engaged twice during the 1,500 miles.
-Rest of mods are in garage.

So, I after about 1,500 miles on the exhaust, it seems the resonator has possibly gone out on me. I get a TERRIBLE rattling when letting off RPMS above 2.5k (when they drop i hear the rattle) And my exhaust is blowing out Metallic, chalky stuff. I understand it blows some crap out when first installed, but not this much, this many miles later.

Well, I take the car out for a drive. WOT through first, notice a -tiny- stumble at 5.5k RPM. I make it to second, where it stumbles like mad, and the CEL will start to flash. It wont stay on, just flash. After it's done stumbling, it's SLOWLY crawl through the RPM's, and in third gear it WILL NOT go past 5k RPM. It just hangs there.

Mind you, I have the 2-step disengaged (turned completely off) unless I'm running the car at the track. So, it does not, in anyway, turn itself on at this time. The LED is in clear site and would let me know.

It seems to me like the engine is being chocked. I checked my CAI, it's there fine... checked all the solder to the wires on my WOT box, still fine. I've crawled under the car and can CLEARLY hear a rattle from the resonator.... I don't have the tools at this time to take it off and inspect it though.

I've contacted NGAmotorsports about this issue to warrant the exhaust... they've been a HUGE pain in my ass. First telling me to contact megan, when it CLEARLY states on the site to contact your distributor for warranty information.... so it's not like I can easily get a new resonator there to see if that's the issue.

Anyone have any idea what's going on???

TheRandom1 · Post by **TheRandom1** » Sat Sep 20, 2008 7:56 am

Sounds like something broke loose and is clogging the cat. I had the same thing happen on my old Camaro. replaced the whole exhaust except the cat ( too expensive when I was 17) and when I would lay off the gas on the highway the CEL would come on. Ended up that the cat was bad, swapped it out and it was just fine.

I would call a friend who can help you swap that cat and see how the car runs after that.

2002TuRboNeoN · Post by **2002TuRboNeoN** » Sat Sep 20, 2008 3:26 pm

was it a new or used megan cat back exhaust??? soundslike a cat see if u can swap out with a friend to make sure the problem goes away so u dont have 2 spend all the money on the cat if its not that....also wer eu runnign really rich at one point in time that may also clog the cat if to much fuel is unburned

OB · Post by OB » Sat Sep 20, 2008 3:52 pm

I'm with these guys. Sounds more like a cat issue if you see chaulky stuff coming from the exhaust. A resonator has metal baffles. They really dont "blow out", but if they did this might be relative. If you have a fiberglass resonator (aka glasspack), these are more likely to fail under certain conditions. Where is it located in the exhaust? Is there one or two?

60trim · Post by **60trim** » Sat Sep 20, 2008 4:51 pm

Where is the resi located in the system? Possible get a test pipe and see if that changes the rattleing noise. Also, maybe do a little seafoam and clear out your exhaust. Eliminate any carbon build up on your valves. Reset your battery and go for a little drive.

summy · Post by **summy** » Sun Sep 21, 2008 12:23 am

did you ever run leaded gas???

drop the downpipe and ram a broom in the cat and finish it off at this point ^^

Mr Josh Zombie · Post by **Mr Josh Zombie** » Sun Sep 21, 2008 12:50 pm

-Megan exhaust is brand new. I don't buy used parts
-One resonator, directly in the center of the exhaust. No idea what it's made out of.

Well, yesterday I took off the resonator.... Clean.

Took a flashlight, looked up into the cat.... clean

Took off the WOT box... rewired all the stock stuff back together.

Now the car mis-fires like mad, CEL is constantly on, boost gauge isn't working.... I was just hoping and PRAYING to make it home last night. Thankfully I have tomorrow off of work and the cobalt can go to the dealership.

Everyone on cobalt SS is with you guys about it being the cat. Thankfully, car is under warranty and it'll be going in tomorrow.

TheRandom1 · Post by **TheRandom1** » Sun Sep 21, 2008 1:17 pm

Good luck!