sunfire 2.4gt trouble code #P0172-system rich

[gavinbr]

hello,

has anybody had problems with the 2.4 GT running to rich [trouble code P0172] or chugging/loping at idle. runs good otherwise

any suggestions or experiences welcomed

thanks

gavinbr

[LD9Grandam]

might be your IAC, or some type of vacum leak. Try taking off the IAC and spray it down with carb cleaner.

[richtazz]

I agree with Ld that the IAC is a good place to start.

[gavinbr]

hello,

thanks for your input

however i have changed the following items

1] gas filter
2] manifold absolute pressure sensor[controls fuel delivery], tested out of specs
3] intake air temp sensor[controls air/fuel ratio], tested out of specs
4] front exhaust manifold sensor
5] engine temp switch[air fuel/ratio]
6] cleaned IAC seems OK, havn't tested its resistance though
7] checked EGR appears OK

next on the list are...........

1] 2nd oxygen sensor
2] Idle air control sensor[IAC]
3] throttle position sensor [IAC]
4] fuel pressure regulator

what else could it be?

vacuum checks oK!

gavinbr

PS: if anybody uses the chilton manual their are some errors in it, the wiring diagrams are general not shown for specific year, the oxygen sensor diagram shown is incorrect and i'm sure there are some others?

for those who donot have an OBDII testor and want to delete codes
just remove the PCM 10amp fuse in the engine compartment fuse box. this is hot all the time and controls the computer memory.

[avery3b]

HELP!!!!! Just bought car. While idling car seems to want to stall/no engine light on. Was fine while driving. Yesterday we just did tune up and now engine light is on. Did you find out what was wrong with yours? Just put all my money into buying it.......