hey guys, long time member with not many posts under my belt. Anyways having some major issues with my 2.2 cobalt since this saturday and cant seem to figure out what the heck is going on with it. have had an issue with it taking a long time to crank over for almost the last month and then this saturday went to go start it and it did start, but then started shaking really bad and finally the CEL came on. Long story short i hooked up my code reader and its reporting a random misfire. Thing i've replced so far are: Spark plugs, Coil boots, Ignition coil itself, and MAP sensor. None of which did anytin or the problem and it seems to be getting worse, the car accelerates really slowly and cant seem to get over 45-50mph.......please help!

 

check the fuel system.

 

forgot to mention ran sea foam through both the brake booster hose and the fuel tank and still nothing after that.

 

ok so i got te misfiring issue 95% solved, just had to replace the ignition control module. Only a new problem has cropped up, got on the freeway and tried to go WOT and had a loss of power when i got to over 4500rpm, got to over 5000rpm and engine started misfiring again until i let off the gas and went down to 3000rpm and the misfiring stopped and CEL turned off. Someone suggested that it may be the MAF needs cleaning or replacing, anyone else can confirm this or have any other suggestions? I took the MAF out and looked at it and it seems to have a whole bunch of waterspots all over it.

 

waterspots on the maf? thats no good sir

 

i didnt think so either so replace or clean?

P.S.

Also wanted to add while i was driving around today i threw a P0411 code saying that the SAI isnt getting correct air flow, im wondering if this could be why im losing power at top end?

 

bump....still waiting for any suggestions guys

 

I would say try cleaning it.. if that still happens u gotta replace it man

 

You have an aftermarket intake? put a hydroshield on it, that's probably why you're getting waterspots on your maf. Put the shield on, then clean the maf, then see what happens.

 

ok so cleaned the MAF and everything and still same issue. one more thing to add in is i tried taking off the check valve for the SAI and disconnected it from the exhaust manifold and low and behold i was now able to rev up past 5000rpm but it was loud as hell and throwing all kinds of exhaust fumes into the inside of the car and of course still losing power, but i did not hear the whistling noise anymore that sounds like when you're blowing through one of those ribbed straws you get with a thermos. I of course had to reconnect the check valve so as not to kill myself with exhaust fumes and the whistling returned. I did read somewhere else on the boards about someone running into a few minor issues with a clogged/bad air pump, any thoughts on that would be appreciated guys and thanks for the suggestions so far.

P.S.

In response to the question about aftermarket intake, no its not aftermarket i just have the front fascia of a body kit that i think has a hole where the stock air intake ends at.

 

check the catalytic converter

 

X2
Sounds like the cat and lucky for you there under warranty.

 

x3 on the cat. We had a sunfire in the shop yesterday that wouldn't rev past 2300 rpms and the only code it was throwing was a cylinder 3 misfire. Put it on the hoist and you could feel the heat off the cat from about 3 feet away. Replaced the cat and the car ran great.

 

yeah thats what i was afraid of, but arent the catalytic converters only covered up to like 80k? cause i have almost 113k on my cobalt

P.S.

Forgot to mention that there has been a slight increase in coolant temps too, usually i sit at around 189 to 192 and after this whole fiasco my coolant temps have jumped by a few degrees up to around 196 when im moving and almost 223 when im at idle in park. kinda sounds like the secondary air pump is messed up too.

 

Gut the cats or get an aftermarket dp..
I have my stock dp if ya need it

 

exhaust restrictions generate alot of heat too, as well as keeping the exhaust gas velocity down so the heat stays. i still say cat.

 

thats what i was thinking about doing with regards to gutting the cats although i wouldnt know where to go to pass emissions in socal if i did that and i do not disagree that it is the cat jimbo i was just including another problem that seems to have cropped up from just this one part. if i do gut it would that alleviate the pressure that building up near the air pump and if so would i have to replace the air pump or just try and clean it out first?

P.S.

Fonzi, how much would you want for your DP and is it able to fit on a cobalt seeing as by your signature it looks like you have a G5

 

Yeah if cat is clogged it could be messing with ur pump.. U can gut it but iirc our dp have 2 cats. and if u cant find a replacement pump i have that as well

 

have the cat tested before you gut it. and if it does become a problem, get a spun mettalic cat installed, less flow restriction and less likely to clog or melt.

 

Cobalt and g5 r the same thing man.. All the parts i have on my car r for the Cobalt.
Pm me if ya really need anything i have all my stock parts and a ss exhaust..
But as for the cat try what Jim said.. if not i will sell it to ya for cheap

 

could you PM me with details on the pump and DP?


where the heck do i get a spun metallic cat and are they even allowed to sell that in california?

 

https://www.zzperformance.com/cobalt...=364&catid=155 its a 30 dollar option for the metal cat vs ceramic but worth it

 

sooo, another DTC code in the ongoing struggle with this thing and low and behold guess what it is....the famous P0101 code indicating the MAF sensor is bad.....guess that puts a final end to the question of whether or not to replace it huh guys? lol.....anyway my dad and i took off the DP this weekend and found that the cats are not clogged at all and took off and tested the SAI pump and tested the motor on it with a DC power unit my dad has and the motor works perfectly fine on it and it open and closes the valve just fine....any other ideas besides the MAF which im going to replace that may be causing this issue?

 

what year and trim level of cobalt do you own? try to borrow a maf sensor before you buy one. test everything before you buy anything imo. also have you had anyother codes besides that one? oh and check for vacuum leaks since you ran seafoam through it

 

i have an 2006 LS trim and i did check for vacuum leaks and only found one which was my fault as i forgot to put the hose clamp back on the leads from the air intake to the cylinder head. Other than that my dad and i checked all over the engine and couldnt find leaks anywhere else. we also checked the relay for the SAI pump and found that it was working correctly. im thinking at this point that the MAF sensor is somehow not sending a signal to the SAI pump on when to open and close the valve on it and it causing the exhaust to leak out into the SAI pump line. as for not being able to rev past 4k now i can definitely attribute that to the MAF sensor from what i know about that causing issues with revving.