Hello, I have read some of the other posts on here about P0172 System too rich, and will follow the advice there, but I needed to ask a question and that post was from 2006, and I did not know if someone would respond.

This Bonneville we have is frustrating. A year ago it was shutting off while driving, we fixed it with a crank shaft sensor, it worked for about a year, and then it started shutting off again. A different code showed, we replaced the thermostat, cleared the code, but it never quit shutting off. So after we cleared the code and it shut off again, we read a code and got P0172....Is this related to the shutting off??? I believe it is a 2001, and it gets kinda crappy mpg.

Help!

does it shut off when warm and then not restart or just randomly quit and then restart? what was the other code?

Start by reading this. https://www.gmforum.com/showthread.p...46#post1390875

Yes, Thank you Darthurs, I did read it and print it out as well as another one, but because you said "no drivablitly problems" I felt like I needed to ask if the shutting off was related.

jwfirebird - At first she noticed it was when it was not warm, and we had got the thermostat change because a code led to that. Now it seems to be random, and most of the time it will restart right away, but the last time, she said it took a few times to restart. Thank you

sounds like your maf sensor is going out. and that would cause you to get a rich reading in the exhaust.

I am not gonna get too excited here, BUT pray, cross your fingers, stand on your head, whatever you do to hope for good things to happen because the mechanic found a wire touching the O2 Sensor, and he cleaned a dirty MAF, and she drove it for an hour and a half without it shutting off

Yes, a plug wire touching the O2 sensor wire can confuse the signals and cause the engine to do odd things. So I will cross my fingers and spit in my hat.

Any chance someone can tell me where to look (if it is possible) for a wire touching the O2 Sensor. The car starting doing it (shutting off while driving) AGAIN!! The code AGIAN was P0172. She also now has a P440 code, and we will do the basic of taking of the cap and redoing and clear the code, and see if the code comes back. But this code wouldn't cause the car to shut off would it?

the 02 sensor is in between the back of the engine and the firewall on the exhaust

assuming you have the na 3800
evap generally wont cause the shut off but check for cracks in the rubber fitting on the throttle body. if that or the lines going to the evap are loose or dry rotted it will cause a major vacuum leak and the improper signal to the fuel pressure regulator.