Fairly straight forward this one. The relationship between these two sensors is helpful in assessing the functionality of the Lambda Sensor & the closed loop systems ability to maintain steady & accurate fuel control.

 

 

Red trace = MAF Sensor Output

Blue trace = Lambda Sensor Output

Note:- The response time from when the throttle is snapped wide open to the lambda sensor reaction, should be rapid. I expect around 180 ms on average. Ideally I find it better to wait for the Lambda sensor volts to be in the low (lean) range before snapping the throttle. This way it can be seen to react to the "forced" rich condition that you are creating.

 

Pico

www.londonroadgarage.com