I've had this thing to 3 different mechs and a dealer and no one can figure it out. Its a 2008 HHR SS it has about 55000 mi on it, the CEL came on about 4 months ago or so and it has the following codes. P0130, P0135, P2251. So it has to do with the front O2 sensor, i have replaced this sensor and looked at the MAF, MAP, and pretty much everything else. This is my wifes car but from driving it heres what happens....on cold starts it sputters but after about 5 sec its fine I have HP tuners and used the scanner and cant find anything NO i have not put a tune on the car or anything like that. other than that I don't know what else to look at. Got any ideas??? Thanks in advace

 

sounds like either the wiring is frayed/chafing or something on the o2 or there is a vacuum leak somewhere. the sputtering on cold start up leads me to think the latter

 

Mine started a little rough each time before I replaced the BPV, at 55k if you haven't replaced it, it's time. Mine stopped starting rough, both times, they happened 25k and 55k. The Forge replacement is nice, buy one and have your dealer install it, they will see the sense in it when they see the quality difference. So you will still have the coverage. My best guess

 

BPV? checked for vac leaks and its good there replaced the front o2 sensor and still the CEL pops up but only after driving for about 10 miles or so.

 

I think he might be menaing the BOV or blow off valve. If that is the case though it is not a part that is SUPPOSED to have to be routinely changed. Infact it should not have to be changed ever. But stock BOV's tend to be made cheaply so I can see a stock one failing prematurely.

 

don't really know how that would cause cel's for the O2 sensors

 

Shoot me a PM with your e-mail address stryder, and I'll send you a PDF of the engine section of the '08 SS service manual, maybe that'll help you figure things out.

 

With today's computers in these cars anything is possible. But the BOV if it is leaking can cause incorrect air/fuel ratios as the computer thinks X amount of air is flowing to the engine but Y amount is actually getting there. This difference in the volumn of air between what the computer is expecting and what is really there can cause various issues. In this kind of cenerio the O2 sensor will be expecting it's own X anount of O2 but there is Y amount of O2 passing by it. Or it could just be what code is thrown up if there is more or less air then what was metered.

 

sent

 

PDF's on the way stryder, hope they help cure that CEL for you.