I got a trouble code 45 from my assembly line diagnostic link: "Rich system indication. The engine must run at least 5 min., in closed loop, at part throttle and road load for this code to set." (chilton's repair & tune-up guide camaro 82-83 all models) I'm not too sure what that means though? I then tested it while engine running in park which showed that it was running in closed loop. If I can get a little more clarity on this, it would be a great help!

1983 z28, auto., crossfire injection, 5.0L

 

I don't have the specifics of the 82/83 models, but for the later models, that code sets when the PCM is operating on closed loop, and the O2 sensor voltage stays above 700mV for 50 seconds.

That would either mean the O2 sensor is faulty, the wiring is leaking voltage to the signal wire (only if you have a heated sensor, which I doubt) or the engine really is running excessively rich in closed loop, and the ECM is not able to lean it out using the long term and short term fuel corrections.

The reference to "The engine must run at least 5 min., in closed loop, at part throttle and road load for this code to set" simply means that the ECM has to be operating on closed loop (which yours is) and doing so for 5 minutes before the ECM runs the diagnostic.

 

Ok... so how do I fix this problem? I tried changing the o2 sensor and I'm still getting the same trouble code. I'm also getting a code 33.(I was getting that b4 I changed the o2 sensor) Whats that about? That code isn't even in the chilton.

 

DTC 33 is for high voltage (= low vacuum) from the MAP sensor. In a speed-density setup, that will cause the engine to run rich, since the ECM assumes from the high MAP/low vacuum that the engine is under load, and when it does the "density" part of the speed-density calculation, it calculates a higher-than-actual air flow, causing the ECM to add fuel the engine doesn't need = rich = high O2 sensor voltage = DTC 45.

Check the MAP sensor. The connectors can dry out and crumble causing intermittent contact and faulty readings. Or the sensor may be defective. Or, if the sensor is mounted remote from the intake manifold (again, I don't know the details of the TBI setup) the hose that connects it to the manifold may be damaged.