Bypassing an Air Injection failure

[Phoenix127]

Would it be possible to close a relay upon air injection pump activation which would switch a resistor in parallel with the O2 sensor thereby tricking the car into believing the air injection system was working properly? I believe this technique has promise in solving an annoying check engine light. However, I don't know the appropriate O2 sensor resistance values during air pump operation or the resistance values indicating an air injection error condition. Any knowledgeable on this matter feel free to weigh in. Any assistance is greatly appreciated.

Thanks

 

[gsxr]

I don't know any way to fool the O2 sensor readings.

Why not remove the CEL bulb if it bothers you? The CEL only indicates emissions faults anyway. If the car is driving ok, check codes on the other modules periodically if you're worried about some other issue popping up. IMO, the W124 CEL is nearly useless, I can count on one hand the number of times it's illuminated and identified an actual problem with my cars in 12+ years of owning .034/.036 chassis. The vast majority of the time, important codes never trigger the CEL as they are not emission-related.

 

[Klink]

I don't know any way to fool the O2 sensor readings.

Why not remove the CEL bulb if it bothers you? The CEL only indicates emissions faults anyway. If the car is driving ok, check codes on the other modules periodically if you're worried about some other issue popping up. IMO, the W124 CEL is nearly useless, I can count on one hand the number of times it's illuminated and identified an actual problem with my cars in 12+ years of owning .034/.036 chassis. The vast majority of the time, important codes never trigger the CEL as they are not emission-related.

X about a million....

 

[gerryvz]

The air injection failure CEL / code is usually because the air tube is blocked with solidified carbon vapors, not the air pump itself. My car has had this failure for several years, and I'm getting ready (finally) to attack the problem this winter and unblock the tube. It's going to take some work, but the red CEL that comes on within a day or two of resetting it every time has finally gotten just too irritating to me.

What's most annoying is that the "failure" of the air injection system is such a short-term thing that only occurs at cold starts, and has ZERO effect on the actual running and performance of the engine.

This condition is usually registered with a code 4 (often accompanied by code 5) at the pushbutton under the hood on US cars.