Car was whistling, and saw there was a broken diaphragm. Replaced diaphragm and car sounded and ran normally a few short trips. Next day, car cranked but would not start and got these two codes. It was weird, as I turned ignition on, it seemed to "catch" and crank by itself for a few seconds. I installed a completed new trap- same issue. Cleaned MAF- same issue.
Help!

 

Just my 2 cents JT I had the whistling Pcv symtom and I had those same codes before I replaced the trap. The whistling stopped but those codes are still there, though one turned yellow. My car runs fine though. If your engine doesn't start it may have a vacuum leak from something you moved or a crack hose or the gasket got kinked or the bolts may not be torqed right. Otherwise may be coincident with another problem wiring maybe? good luck!

 

you didn't mention which engine you have but the P0171 and P0174 are pointing to a lean fuel trim fault. Given your recent work suggests you have an intake air leak - possibly in the PCV hoses etc. Here's a general list of causes. I'd probably rule out the O2 sensor, fuel injectors etc and focus on air leaks and the PCV plumbing.

• Intake air leaks
• Faulty front heated oxygen sensor
• Ignition misfiring
• Faulty fuel injectors
• Exhaust gas leaks
• Incorrect fuel pressure
• Lack of fuel
• Faulty Mass Air Flow (MAF) sensor
• Incorrect Positive Crankcase Ventilation (PCV) hose connection

 

thanks for the replies. I ruled out the MAF. I don't know how my new Oil Trap could be letting in enough air to not start, but I may go back and try to torque it to specs (I think I read 14ftlbs somewhere?)

It seems to me it may not be getting fuel. I'm going to try some starting fluid and see if it fires up. Should I hear the fuel pump when someone turns key on? I was listening at the fuel tank underneath, and in the fill hole, and could hear nothing.

Lastly, is there a common relay fuse or something for this that I could try replacing? The fuel pump never seemed to give me any issues so not sure it would all of a sudden go out, and thought maybe there was an electrical issue. Also, I read about PEM being a common failure. Anything related to fuel, I appreciate help. Dont know how else to test for vacuum leaks other than a visual. THANK YOU!