Hey, look another 0299 thread!

[DirkDeadeye]

Take this with a grain of salt, I know cars, but not this new generation of cars..

Also, worth noting, the car is bone stock, no tune, nothing, nada. I'm running regular gas, because I think even I read here regular is fine. If that's an issue, I don't mind putting premium in it.

So, a couple months after the warranty on my 2012 LTZ 6M expire, I get a CEL, 0299.. I look it up, and underboost. Now, I don't have a proper boost gauge, what I do have, is an OBDII bluetooth dongleamajig, and the computer is telling me I'm getting around 4-6psi, at most..around I'd say 3-4k RPM I don't wind my car out, although when I do, in lower gears, it peaks about 6psi, and goes vac when I'm up in the 5,000's in low gear. In 6th gear, around 2-3k it reports about 3-5psi..maybe more, I mean I'm having to look at my center console where my phone is, so I don't want to cause an accident not paying attention.

I don't know how the turbo in this car is supposed to behave, or any car for that matter..it seems when it's under load the turbo does spool up but when I break out of the torque curve the boost is gone. I'm guessing that's right? Again im sorry for being a total layman, I know a lot about a lot of things, but this isn't something I know much about.

Car is out of warranty, it works fine..It could be faster off the line, but I'm past that part of my life, and I get great mileage...however some power to lane change would be great, and I'm thinking I'm being robbed of that. If need be I can figure out how to log **** on this app, if what the computer says about boost pressure is accurate and provide those logs..or should I just have my mechanic look at it? He's a good guy, doesn't bend people over. Although warranty work would be better, but that ship has sailed.

 

[MaD]

A tune would give you the extra power and mileage you are looking for, as for the turbo, have it looked at before you get the tune. I'm sure others here will have more to say, but that's a start.

Sent from my SM-G900T using Tapatalk

 

[ScarabEpic22]

Probably looking at a new turbo from the dealer, I'd get an appointment and have it checked out. You should have ~11-15psi boost from 2500-5000rpms with the stock turbo and depending on your altitude (the ECM varies boost to deliver what desired TQ value it wants based on operating conditions).

Once you get that issue sorted out, look at BNR for a tune. More like 20-22psi of boost and it comes on harder.

 

[DirkDeadeye]

Probably looking at a new turbo from the dealer, I'd get an appointment and have it checked out. You should have ~11-15psi boost from 2500-5000rpms with the stock turbo and depending on your altitude (the ECM varies boost to deliver what desired TQ value it wants based on operating conditions).

Once you get that issue sorted out, look at BNR for a tune. More like 20-22psi of boost and it comes on harder.

I'm out of warranty, do you, or anyone else have an idea how much that's gonna cost?

 

[Tormach]

Some info is in this ongoing thread regarding the turbo and P0299, see below. I just had mine done and was fortunate that the GMPP I got when I got the car covered it.

If you dig enough I believe there is also service/replacement instructions online as well, I have stumbled across them once before.

There must be a way to fix the wastegate play.

What a big disparity. $350 for new Turbo from Rockauto vs all the other places selling it for $900+

Not that difficult on these cars. It's relatively straight forward. There are a couple manifold bolts that are a royal PITA to get to when doing the procedure.
Replaced mine in the work parking lot in a few days because of limited tools. If you have everything including the coolant, shouldn't take you more than a day to do by yourself.

Pretty sure forge now offers an aftermarket wastegate actuator for these cars now, but I could be wrong on that one.

http://www.sonicownersforum.com/for...gine-discussion/22228-turbo-gone-again-3.html

 

[DirkDeadeye]

I wonder if this has anything to do with a solenoid that had to be swapped when I bought it. I wish I had this code when I was under warranty. I sure as hell am not gonna trust myself to replace this thing.

 

[Tormach]

I am not sure, might be. Some one else with far better understanding would have to chime in.

As is stands even with mine replaced, I am backtracking threw each system connected to it seeing if there is an underlying problem and/or if other related systems where hurt because of it failing opcorn:. Have found that my intake manifolds pcv nipple is missing so far (this is most like from when the cam cover orange disk failed and wish i new at the time that it could happen, would have had it fixed then :blankface.

Hope your able to get yours resolved to something easily fixed.

 

[Maddmatts]

When P0299 is triggered (no longer pending), the engine is put into reduced power mode until the code is cleared. Try clearing the code and see if the problem persists.

Over the next few drives, use your scanner to check for pending codes since they don't trip the check engine light.

 

[DirkDeadeye]

I had to use another scanner to wipe the code, and when that happened, I had boost. Like, from standstill, feathering the throttle, I could build it up.

Again, i'm going by readings from the Torque app on an android phone, through an OBD II bluetooth adapter. I don't even know weather nor not these boost readings are even accurate.

Right now the only way I get boost is if the transmission is under load, which is the best way I can put it. I'm not really feeling a reduced power mode, as this car is just plain slow, codes or no codes, even drove another sonic with the same trim, engine..etc Unless you mean like it won't start in 2nd, which takes a bit of clutch to do..

It drives fine, but seeing that it had no issues when the ECM was told otherwise makes me wonder what the problem really is.

 

[Blue Moon Sonic]

A tune would give you the extra power and mileage you are looking for, as for the turbo, have it looked at before you get the tune. I'm sure others here will have more to say, but that's a start.

Sent from my SM-G900T using Tapatalk

This right here. Make sure you get it checked before you get tuned. Otherwise You won't have a P0299 code pop up at all and you'll be scratching your head wondering where the damn boost leak is.