System Running Rich (gen 7) 2000

[Addictt]

Hi,

I recently had a AIR FLOW METER replaced in my Toyota Celica 2000 model VVTi as the engine light came on and was informed at my garage that it needed a new one.

However, since then the engine light has not gone off, recently however the light sometimes goes off, then after about a 100 miles comes back on again....

Anyway, yesterday i decided to purchase a OBDII reader, and the error code it gave me was P0172 and said that it was 'System running Rich'.

Pllllllllllllllllleeeeeeeeeeeeeeease can someone help me with this...

I've had a post or two before where i've had like 150 views but no responses.

Any help would be appreciated.

Please can someone just guide me to what it could possibly mean, as i was thinking of having a K&N 57i Upgrade fitted in soon, but i wanted to fix this prob first.

Thanks a million

[LEX-celica]

rite ok basicaly what is happening is the sensor is not giving enough are to the fuel system and it is not giving a clean burn so you get unburnt fuel!(have you noticed you been geting less miles?) also if this is the case it can damage your cat so be careful (if you smell unburnt fuel cumin outa the exhaust dont drive it unless you have to. putting an induction kit on would actualy help the problem i fink because in theory more air to fuel mix. best thing to do is to get that sensor looked at again because it could be faulty or not set up corectly or something could have effected the ecu which may be pumping in more fuel than is needed(also check fuel sensor and O2 sensor) another thing that may fix it is to unhook your batery for bout 2 mins to allow ecu to reset and see what happens!

hope that helps if not get it checked out again!!!

[Templeton]

I've gone the other way Addictt, i've got code P0171 System too Lean at the minute.

According to the actual Toyota manuel P0172 is caused by one or more of the following-

Injector leak/blockage

Mass air flow meter

Engine coolant temp sensor

Ignition System

Fuel Pressure

Gas leakage or exhaust system

Open or short in heated oxygen sensor (bank 1 sensor 1) circuit

Heated oxygen sensor (bank 1 sensor 1)

Now I've got no idea what most of that means I'm afraid. But you could try cleaning the MAF sensor, and something like Redex is good for cleaning injectors.

[LEX-celica]

my mate at the garrage says that it may be the fuel pump or sensor. and yeh use some wyms injection cleaner redex isnt reali that great!

[sjrainsford]

If this has started happening since having the MAF sensor replaced, I'd look there to start with - maybe it was damaged or a bad connection? Plus reading fault codes can give spurious errors, so they may have replaced the MAF which was borderline but that may have not been the original fault, even though the fault code may have pointed toward it.

Then I'd start looking at lambda, ie the o2 sensors. Those would be the two most likely points of failure or error. But it doesn't mean there couldn't be something else wrong. It's always best to start looking at the common areas first. B)

[Addictt]

Hey.... thanks for the helpful info you guys...

I have managed to fix it, i brought a new MAF Sensor and it did the trick..

I've also ran the diagnostic reader and there are no errors, however i floored it today (about 4-5000 rpm) and my mate who was behind me said there was some sign of blue smoke coming out..

And today i floored it again, and i could smell a scent of petrol? any ideas folks?? all seems to be running smoothly though, so might not be anything.

Thanks