Hey guys, i have a Cobalt SS/SC with stage 2, intake, and torque dampener. I was under the impression that the car hits about 12.5 psi stock and about 15psi boost with GMPP stage 2. Anyway enough blabbering, heres the problem;

When under hard acceleration approaching redline (7000 rpm) in normal conditions, my stock boost gauge is reading 20+ psi of boost.

The arrow on the boost gauge is literally off the charts.

My CEL has been on ever since i installed the Injen CAI, but the car has been performing PERFECTLY so i have been just trying to ignore it until i get a chance to take it in.

Any input would be nice, i hope its just a gauge issue and not a blower issue.

Thanks,
Elf

Hmm. I was under the impression that stage 2 with the stock pully is only like 15+ But if you have a 2.8'' pulley or smaller I would understand the 20+psi

To fix your cel problem. try disconnecting you MAF and battery. Battery first, then MAF. Then wait a bit and reconnect the MAF and then your battery. That should take care of your cel problem.

To fix your cel problem. try disconnecting you MAF and battery. Battery first, then MAF. Then wait a bit and reconnect the MAF and then your battery. That should take care of your cel problem.


Thanks for such a quick post dude, i really appreciate it. I'm running the stage 2 pully though so it cant be pully unless i just got a freak pulley.

Also, i have a noob question. Is the MAF the sensor that i physically removed from the stock airbox and placed on the CAI piping when installing the CAI?

Yes it looks like a computer chip almost, i had the same problem when i put on my fujita till i disconnected the battery for like 30 min. but 20 wow i have the stage 2 with 2.8 and i am lucky to get 16-17 at 7000rpms

Yes it looks like a computer chip almost, i had the same problem when i put on my fujita till i disconnected the battery for like 30 min. but 20 wow i have the stage 2 with 2.8 and i am lucky to get 16-17 at 7000rpms

Yea i know its crazy! I'm thinking my gauge is bad. Thats all i can think of. The only other possibilty is GM sent me the wrong pully in my stage 2 kit, but thats next to impossible. Either way i'm gonna do that MAF thing you guys are talking about and see what happens

Another quick noob question, is it possible to mess with the MAF without removing my FREAKING wheel and wheel well? I swear it took me 5 minutes to actually put the Injen in while it took me about an hour and a half to jack the car up and remove the wheel and wheel well.

Perhaps i can just remove the wheel well and leave my wheel on?

ehh im pretty sure i had to take that whole mf apart. considering thats the longest cai install i have ever seen.

but i am not sure.

I didnt even have to take my wheel off to put my K&N Intake in, I just turned the wheel all the way to the left and it gave me plenty of room. :)

I didnt even have to take my wheel off to put my K&N Intake in, I just turned the wheel all the way to the left and it gave me plenty of room. :)

i have a aem cai and i have to install it so i hope i dont hav to take my wheel off... i just bought my new rims and i'd have to remove it... cuz u know shit happens..

Yeah I know, like sliding them across the concrete and scuffing them. I didnt want to take them off because I have a "free tres for life deal with the dealership" and I didnt know if they could tell if I took them off by the torque of the lugnuts. I'm just quary about those things... But it only took me like 30 min to install, most of it was taking loose the fender liner :cool:

i have a aem cai and i have to install it so i hope i dont hav to take my wheel off... i just bought my new rims and i'd have to remove it... cuz u know shit happens..


the cai on a ss/sc is different from the 2.2l and the 2.4l. the 2.0l goes to the right side of car and underneath. the 2.2l and 2.4l go to the left and seem to have more room in the fenderwell.

Okay guys a quick update. I recently had a friend of a friend use his diagnostic thingy to see exactly what code i was throwing. I think is was a P0449. I should of wrote it down but was trying to play halo 2 and you know how distracting that can be....

Anyway, i looked it up on the DTC list and this is what i found

"P0449 Evaporative Emission (EVAP) Vent Solenoid Control Circuit -PCM"

So, uhhhhh, i have no idea WTF that means. I'm thinking about taking it in to the dealership but aside from the weird boost readings and a slight hesitation at 6000rpm in 2nd gear sometimes, there is really no issues.

I'm seriously worried that they will just blame it on the cold air intake and charge me for the diagnostic and reflash. I'm no mechanic but i know that a Cold air intake is not going to screw up a boost gauge like this. Anyway, let me know what you guys think. Like i said its no emergency but would appreciate some advice.

My guess would be that your cat is clogged, that'll throw the boost up high like that. And they may try to blame your CAI. Just to make life easier on yourself, you might want to swap back to the stock intake and then take your car in to have it checked out. In reality, I doubt the CAI caused any problems either, but that doesn't mean they wouldn't argue with you about it anyways.

The Evap code is something in the gas tank emissions system, nothing to do with the engine. Take it in for that, and mention that the car feels like it lacks power sometimes at full throttle and you get a funny smell from the exhaust. That way they will check the Cat out. The light they will fix, probably by replacing the evap purge solenoid, nothing major there. Edit: also, about that hesitation, i have had that since day one with my car, every once in a while. Nothing that you can really do about it.

Thank you "mken" and "Italian Joe", you both seem to be EXCELLENT sources of information. I never even considered the idea of my cat being clogged. I'm going to schedule an appointment tomorrow. I didn't realize how serious this could be.

I have noticed that my exhaust note has changed significantly. Sometimes its fine but recently it has been weirdly quiet. I only noticed because i rode with my friend on a test drive of an 07 SS/SC and the exhaust was significantly louder than mine. Of course it could just be my mind just making up things.

I don't think that i'm going to replace my orginal airbox. Its a good idea but its just too much work for an amatuer like me with simple hand tools and no garage. My family has bought 5 cars from them in the past 4 years so they should treat us fair.

Perhaps this would be a good excuse for me to buy the GMPP catback exhaust system?

More than likely you have a plugged catalytic converter. I have heard of more than one Cobalt with a plugged CAT. This would explain BOTH of your problems.....

EDIT: Whoops! Next time I will read ALL of the replies before posting.... LOL

More than likely you have a plugged catalytic converter. I have heard of more than one Cobalt with a plugged CAT. This would explain BOTH of your problems.....

EDIT: Whoops! Next time I will read ALL of the replies before posting.... LOL

Its cool dude. You basically just gave me a second opinion completely devoid of bias. Thats three people saying the same thing.

Would a GMPP catback exhaust system fix this? Or is it something else that needs replacing?

Also, what causes clogging? The car only has 7500 miles on it and i thought cat clogging was a more common problem among high mileage cars? Perhaps i am running rich or God forbid my exhaust system is too restrictive for my mods?

another guy had it clogged with 500 miles or so. it happens. kind of common i guess with new cars at dealerships. have them check it out. should be no big deal.

the cai on a ss/sc is different from the 2.2l and the 2.4l. the 2.0l goes to the right side of car and underneath. the 2.2l and 2.4l go to the left and seem to have more room in the fenderwell.


thanx whodis... i didnt even snap that the cai goez opposite side of the 2.0... i guess i was just more excited to install my cai.

thanx whodis... i didnt even snap that the cai goez opposite side of the 2.0... i guess i was just more excited to install my cai.
i only know because i have a 2.2l also. and i put an injen short throw on mine. i love it. wakes the car up just a bit.

Yeah that explains it Elf. My mom's 03 Impala has a clogged cat aswell. I believe it is clogged with Carbon. I drove the car and ut has a lack of power. Also, the car is an auto and shifts pretty quick just riding easy, and I have to hit the gas slightly harder just to get it to shift or else the car hangs out at 3000 rpm plus. GM will void your warranty unless they were the ones who installed the CAI. I've talked to Chevy and Saturn about this, and they said its GM policy.

Yeah that explains it Elf. My mom's 03 Impala has a clogged cat aswell. I believe it is clogged with Carbon. I drove the car and ut has a lack of power. Also, the car is an auto and shifts pretty quick just riding easy, and I have to hit the gas slightly harder just to get it to shift or else the car hangs out at 3000 rpm plus. GM will void your warranty unless they were the ones who installed the CAI. I've talked to Chevy and Saturn about this, and they said its GM policy.

Are you serious?? That would be rediculous if they did that! How could a CAI contribute to carbon in the exhaust? I may just go ahead and replace the stock airbox and remove the torque dampener too. Thanks for the heads up though.

But i find that so weird that they had no problem with a Ram-air kit/K&N filter/whisper lid on my V6 camaro but they will pitch a fit if i have a CAI intake on a cobalt.

On second thought i may just try to stand my ground on this one. A CAI and a torque dampener are going to extend the life of the car if anything, not hurt it.

Even if i have to eat the repair cost, i'm going to enjoy having the manager tell me to my face that a chrome pipe and a brand new clean air filter caused my catalytic converter to clog up after 2000 miles.

I will update you on how things go. Tommorrow i'm getting my oil changed, tires rotated, and one more diagnostic at the local pro-lube. So when i take the car to the dealership on thursday all they have to focus on is my CEL and cat.

Some dealers are cool, some aren't. I only suggested going back to the stock intake because I've already had to argue about my Injen at a dealer around here about it. If you're dealer has been treating you right, and like you said, looked the other way on aftermarket parts on other vehicles of yours, then you shouldn't have anything to worry about. I really can't see how an aftermarket intake could cause the cat to go bad, but then I'm just an amateur in this area, all I know I picked up on these boards over the past year since I got my SS. Magnuson-Moss Act says that they have to prove your aftermarket parts caused your problems, but if they decide to be dicks anyways, you'd probably still have to jump through hoops with a lawyer just to set things straight.

However, I do want to mention that there has been alot of talk about Cobalts being plagued by bad "crank position sensors" (or that's what I remember it being called) that were directly connected to the short life span of the catylitic converters.

the car comes with a cai so just mod the box/filter and be done with it and save the money for a real hp add-on i read all the threads on here and more people have airflow codes because of aftermarket cai that might add a whole 2-3 hp at wheels i got that from a k+n cone filter and airbox mod and spent a whole 49 bucks with an hours time and if your blower is really turning 20+ lbs of boost you'll be back at dealer sooner than you think getting a new blower cuz the m62 will not handle 20+ for a couple steady runs it will overheat and fail i had same cat prob as everyone and it took my blower with it at 6000 miles o2 sim, gut warrantied cat and no cel and no tsb for me glad my blower and cat was under warranty amazing what an 11 bucks online can buy to save you so much trouble and make your car faster

gm cats are clogging with carbon on many makes and models o2 sim and gut it did mine as soon as i got it back from dealer where they replaced blower and cat i strongly recommend this $11.95 fix

Well i just got back from the local lube place and they confirmed it was the Evap emission thingy, so its going into the dealership on monday.

Foundawinner, your saying that i should just cut out my catalytic converter and replace it with exhuast piping and an o2 simulator? That sounds like a good idea but doesn't a catback exhaust system replace the factory cat? Either way, i don't think the dealership, regardless of how cool they are, would take a liking to me cutting it out.

Oh and mken i totally agree with you on the CAI not being able to cause carbon build up. I mean, its just a freaking chrome pipe and a higher quality filter, so i do not forsee the two being intertwined. I mean, how the F does an intake cause exhaust problems???

catback systems retained the original cat, hence the "catback". they bolt directly to cat and replace old exhaust.

catback systems retained the original cat, hence the "catback". they bolt directly to cat and replace old exhaust.

Thanks, thats exactly what i needed to know. I am really considering a high flow cat cause if this happens again i may not notice and could fry my blower or worse.....

Its funny how the factory part is endangering the lifespan of the vehicle.

Well i just got back from the local lube place and they confirmed it was the Evap emission thingy, so its going into the dealership on monday.

Foundawinner, your saying that i should just cut out my catalytic converter and replace it with exhuast piping and an o2 simulator? That sounds like a good idea but doesn't a catback exhaust system replace the factory cat? Either way, i don't think the dealership, regardless of how cool they are, would take a liking to me cutting it out.

Oh and mken i totally agree with you on the CAI not being able to cause carbon build up. I mean, its just a freaking chrome pipe and a higher quality filter, so i do not forsee the two being intertwined. I mean, how the F does an intake cause exhaust problems???

it doesnt cause any problems like that, many cobalts have these issues like said before. i have heard of several cloged cat problems. dont sweat it tho, thats definatly under warranty. they will just replace your downpipe.... dont take your cat out, its not a good idea. you will get black sut on your bumper, wheather you clean it everyday or not. and also, the 02 depends greatly on your a/f ratio, so its kinda important that it works properly. just get a ZZP downpipe with a highflow cat if you really want to increase the flow. :D

it doesnt cause any problems like that, many cobalts have these issues like said before. i have heard of several cloged cat problems. dont sweat it tho, thats definatly under warranty. they will just replace your downpipe.... dont take your cat out, its not a good idea. you will get black sut on your bumper, wheather you clean it everyday or not. and also, the 02 depends greatly on your a/f ratio, so its kinda important that it works properly. just get a ZZP downpipe with a highflow cat if you really want to increase the flow. :D

Hmmmm, how inconspicuous is the ZZP downpipe? Is the cat inside the dowpipe or after it?

I am really considering it because whats going to keep the new cat from clogging again? And what exhaust part is going to need warranty work besides the F'ing cat??? So i won't have to worry about causing another failure.