Code 45 Rich exhaust (Page 1/1)
jaydaug2008 AUG 08, 09:28 PM
Hello I replaced the IAC valve TPS sensor O2 sensor..EGR is next tomorrow hopefully.. Cant find anywhere on the planet the EGR solenoid..From idle I cannot just stab the gas. It wants to die but if I ease into it then it is fine...Any ideas? 1986 SE V6

[This message has been edited by jaydaug2008 (edited 08-08-2022).]

Patrick AUG 08, 09:46 PM

Any resolution to This thread and This thread?
fierofool AUG 09, 07:28 AM
Since you're apparently new to the Fiero world, when you replace the IAC, you must adjust the pintle length to 1 1/8 inch or slightly less, measured from the shoulder where the gasket seats. Using the wrong procedure to adjust it or not adjusting it at all can possibly destroy it. Also, when replacing the TPS, you must adjust it so that the voltage measures 0.5V at idle position and 5.0V at wide open throttle. This must be done with key on but engine not running. Input from these two sensors is used by the ECM to adjust fuel trim and can cause a balk when depressing the accelerator.

The Coolant Temperature Sensor in the passenger end of the lower intake just above the water pump is the main controlling sensor for your fuel trim. If it's defective, it can cause a rich or lean exhaust. Based upon engine coolant temperature, it lets the ECM know how to adjust the air/fuel mixture.
sanderson231 AUG 09, 05:42 PM
Code 45 gets set if the O2 sensor reads above 0.7 volts for 50 seconds and system is in closed loop. Multiple things can cause this:

1) Fuel pressure way too high
2) Imbalanced fuel injectors
3) Leaking injector
3) HEI shielding - tachometer will probably read high.
4) EVAP canistor full of fuel
5) MAP sensor reads too high - try disconnecting it
6) leaking diaphragm in fuel pressure regulator causing fuel to run down vacuum line to intake
7) Intermittent TPS output.

See a factory service manual for more details

------------------
formerly known as sanderson
1984 Quad 4
1886 SE 2.8L
1988 4.9L Cadillac
1988 3800 Supercharged