Car is a 91 Z28 305 TPI 5 speed.

Was wondering what code would be most likely if it was leaning out due to A.I.R removal.

Would it be code 13 "Oxygen sensor signal stays lean during warm engine cruise" or code 44 "Oxygen sensor lean"?

Lastly how much does the gear cost to burn proms for that era car and how many times can you write before its toast?

Thanks in advance.

 

A.I.R. removal will not set a code because it is not monitored.

 

I was under the impression that it fed in extra signal when the pump is triggered to compensate for the extra O2 in the system and that just removing the pump can cause the car to run lean under certain circumstances?

If it does run lean from such an instance would it be code 13 or 44?

 

if you removed the AIR pump then you are going to be running leaner than 14.7 whenever the ECM is commanding for AIR to be diverted to the exhaust manifolds. This is because the O2mV threshold has been reduced ... but you don't have the extra O2 in the exhaust that would require this change in threshold. So, the INT will subtract fuel to get the O2 voltage within the proper range (which is now 100mV lower).

 

The air pump function can easily be disabled if the mat setting in maxed out in the programing.

 

Yes exactly, so in this case which code is it more likely to show if any?

I am struggling because my car is in Australia and I live in Hong Kong.

Its a 91 Z28 so its speed density and nobody locally seems to have a clue how to tune one or even seen one.

I bought a $600 programmable emprompt ecu but the car would not run at all right with it plugged in and i didn't have the cables to access it or knew anybody who knew what to look at even if i did so I put the stock one back which ran fine.

I also tried to buy a chip from fastchip with the air coded out but the guy wont sell me a chip cause he thinks something is wrong with my car.

The story is I had air pump removed, it ran fine then recently i changed to a holley 52mm intake and got a ported base intake and SLP runners.

Now on the highway it throws code 13 on occasion.

Its a brand new O2 sensor so I am trying to work out if the wire that goes back to the ECU might be bad or if the code I am seeing is something to do with the air pump.

 

Removing the air will not throw a code, you may need to datalog during lean cruise reduce the ve at the kpa range may solve the issue.
Have you removed the egr ? It could be a bad o2 ground behind the passenger cylinder head as well.

 

So in short, I have some kind of bad 02 or connection for it to be throwing a code 13?

 

Loss of o2 signal, overly rich condition, soot on the o2, or bad ecm or ecm connection are possible causes for the code 13.

http://chevythunder.com/o2_sensor_diagnostics.htm