Running Rich! Toyota Corolla T Sport 1.8 Vvt-Li

[dantheman1312]

Hi everyone!

I have been having a few issues with my car! It seems to be running rich (judging by the plugs being black and the strong smell of petrol). It has always run slightly rich since I owned the car. it also revs at 1800RPM from cold. at idle when hot it revs at 1000.

the fuel issue got much worse when I fitted an aftermarket K&N air filter.

When i fitted the K&N air filter it threw up an engine code (P0172) System too rich. it also had a couple more problems that go with this.. the engine would bog down in the lower revs while pulling off, hesitating.

Since I put it back to standard the engine management light has gone off. but it still runs rich as always! so I did the following things:

Cleaned the MAF sensor, checked for increase/decrease.

Checked the O2 sensors had a voltage reading (12v) and ohm reading (16 OHMS)

Checked for any Vacuum leaks.

Checked Oil Level

Checked Coolant level

Bits I haven't Checked:

​Throttle Position sensor (TPS)

O2 sensor Readings

MAF Sensor Readings

Coolant Temp Sensor Readings

If anyone has any advice on this it would be greatly appreciated!

Thanks Dan