P0172 code

[hockystik]

I've got a 98 Malibu with a 2.4 four cylinder. It came up with a P0172 code (system too rich, bank 1). I changed both O2 sensors. Two days later, the same code came back. The check engine light is on sometimes and off sometimes. The engine also cuts off while driving at times (it starts right back up), which may or may not be related to the code problem. Any other ideas? Thanks for any help.
Mark

[bcopeland]

Sometimes its as simple as a gas cap. Go to AutoZone and have the codes read - then test further.

[hockystik]

I've got a scanner and that's the code that comes back. I can erase the code but it'll come back within an hour or within of couple days. I checked the gas cap and the seal looked pretty good. I went to AutoZone and the guy there said since I changed both O2 sensors and the same code came back, to come to this site and see if anyone else had any other ideas.
Mark

[bcopeland]

Do you have the cold air intake on it? Do you have the Mass Air Flow switch plugged in?

[hockystik]

It looks like eveything is plugged in. The guy at AutoZone also said it sounded like a possible vaccum leak and to make sure I check all hoses. He also said to check the connections to the fuel injectors.
Mark

[galantin]

check the short little vacuum hose that goes to the map sensor, right by the throttle body, it is common for these to crack

[hockystik]

Great find Galantin! Hose was cracked on the throttle body side. I hope this takes care of it. Thanks for your help.
Mark

[galantin]

no problem, if it is cracked it will allow air to enter giving a low vacuum reading to the sensor. the computer thinks manifold vacuum is lower so it in turn adds fuel causing a rich condition.