DarrenGC

Hey guys,

2009 Cobalt SS,GMS1, catless dp, k&n

Already tried bypassing the solenoid and ran BPV straight to manifold, made minimal difference, will sometimes boost, usually wont.

Pulled bpv out, cleaned it and replaced, bpv looks very clean, previous owner did say he had it replaced at some point but im going to assume its original. Should the OEM one be lubricated with something like the forge? I didnt put anything on it since it was dry and clean when removed.

Didnt seem to change really, made boost once but misfired hard then released pressure on its own - this was with solenoid hooked back up

Is there another sensor i should be checking? I pulled my upper and lower MAPs out a couple weeks ago to clean and then a week later the 2261 and 236 started coming up, the later coming up a couple days before the 2261.

Ive had problems for a few months now with it misfiring sometimes under hard pulls, always assumed it was either bad intake valves or a bad map sensor (sometimes threw p0106/p2199 codes and sometimes got better when i cleaned them periodically).

Could a boost leak cause the symptoms i am currently having? Hasnt pulled a p0101 code.

Sl0wbaltSS

Make sure the stock spring and bpv is being used. Lube it. Plug it in directly to the intake manifold.

AS of for the p0236 you might need a new boost solenoid. The thing that's on your turbo.

Dutchman

I've been chasing this problem for a while too, how much trouble is it to change?

DarrenGC

I had it plugged directly to the manifold, no change so I went back to using the solenoid. Where on the turbo is the boost solenoid?

Dutchman

**********************************/threads/tsb-lnf-wastegate-actuator.586/

Saw this, shows a pic of it

Dutchman

If you google Chevy LNF wastegate actuator it should show you a link about a TSB regarding it on
Chevy cobalt forum .com

DirtySS

Sounds like a boost leak to me, i had a similar problem where car would go into limp mode after two key cycles, i would check all your hoses and clamps, mine ended up being the pressure piping going up into my manafold being too loose and leaking air under pressure, as for the misfires, check your plug gap. These are two of the eaisiest things you can do.

Also make sure that your map sensors are plugged in all the way, maybe try cleaning them off with maf cleaner.

DarrenGC

Update:

Has thrown a p2199 and a p0106 again, wondering if thats a sign to the root of my problem. Going to pull the bumper and lower cp off next week and take a look at everything, check the wiring to the map sensor and clean the sensors again.

Would a bad map sensor cause the bpv to "stick" open by mis-relaying boost levels to the ecm?

DarrenGC

Cleaned and re-wired tmap sensor, cleaned map sensor in manifold.

Car is ONLY throwing p0238 codes on the short drive since them, which makes me still think a boost issue, but what?

DarrenGC

Update: Car runs ok, throws a P0238, sometimes a p0236 and goes into limp mode, clear code - car runs ok again.