P2228 What is it? Why would someone get this?
 

Questions in the title. A member who hasnt created a thread here yet for some reason is having issues with his car. Not the original owner and unsure of everything thats done. Does know the engine is a built LDK has an intake and has a downpipe. Heres the run down:

1.) ECU reset the car runs hard. 21 psi in freezing weather. clearly tuned. "spin tires to 30 mph"
2.) Car has 2.5 MAP bar sensors, he found one cracked (intake manifold) and replaced it. Upon replacing it, there was no o-ring on the cracked sensor.
3.) He has done a boost leak test with soapy water, no bubbles seen.
4.) The By-pass valve looks modded. It is the factory by pass valve from what I can tell, painted black, has the tell tale rubber diaphragm. The stem on it is replaced with a threaded 90 degree fitting.
5.) The only CEL he gets is this p2228 which is low atmospheric hoo-haa or whatever.
6.) with the intake manifold sensor replaced, the car drove fine for about 40 miles.
7.) Another symptom is the BPV makes an additional screech noise after releasing. also the car seems louder. I was leaning towards boost leak but the P01XX code is not there so I dunno.

So is there anyone with any experience with p2228 on 2008-2010 cobalts? Appreciate the help.

Check grounds and the battery, the code is for low voltage check fail to the barometric sensor. If it is a bad barometric sensor he's looking at a new ecu as they're built into the ecu.

forwarded the info to him. hopefully just needs a new battery. He'll get that checked. If not, I think the most affordable option for a new ECU is get a canned ZZP one mailed to him. Anyone else have a more affordable suggestion?

Check all the wiring. Get an actual scanner on the car and look at the data.