So I got a CEL the other day. P0172. Called my dealer service guy. He said the code said it was running rich. Not a big deal. My door panel wasn't in yet so I waited until it came in to have them check the code and install the panel at the same time. Dropped the car off Friday morning. Quarter after 5 he calls me. Said they finally found the problem. Fuel rail was reading 120PSI! Fuel pressure regulator was stuck open. He didn't know what the tolerance for the rail was, but said it wasn't much over that. Looks like I'll be without my car for a while now. They stuck me in a new '06 Cobalt LS for the weekend. Supposed to turn it in today and get a rental. Hopefully it is better than a 4 door automatic...
Dealer called today. They replaced the fuel module with a new one. Said that the pressure dropped a little bit but did not solve the problem. GM says they do not have any documented cases of this happening before. Their next step is to try another fuel module. So I'll be driving this LS for another week and a half
Is there a fuel pressure port (shrader valve) that us owners can use to measure the fuel pressure? Or did GM leave that out?
I'm stunned that the stock fuel pump could even put that much pressure out.
I believe 47 or so psi is normal........
06 Cobalt SS/SC G85 Arrival Blue
90 W40 442 14.5 @ 97
69 Nova Street car, 9.91 @ 133, All Motor
Not a big deal. My door panel wasn't in yet so I waited until it came in to have them check the code and install the panel at the same time.
I am surprised they are replacing your door panel.. My rep said GM is not going to replace anymore until they get re-designed. I've had mine replaced once already, and it shrunk up worse then the original one.
Guess I will have to call my rep and see what is going on..
Hope everything works out for you .
I have no idea how/where/what they tested the pressure with. They did say that if the regulator was open, it could reach 200psi. Oh, it seems there is not a seperate pressure regulator near the rail like I am used to. The pump and regulator is in the same device now.
On the door panel front, the service tech did say he didn't think they one they sent looked great. Guess it's possible they have a warehouse full of badly cut panels somewhere. I'm sure paying dealer service depts to install door panels that have to be replaced anyway isnt very cost effective...