Is inducing an air leak not forcing it lean? I've not simply disconnected the MAF, I've blocked and unblocked the breather.
And my Voltage scale has increased.
What are the specifics you'd like to see?
Robski wrote:that's not what I asked for in the slightest, disconnecting the MAF proves nothing much & masks faults.I wanted to see the O2's .
You crack on !
Hi Robski, managed to get some time on the Astra this afternoon.
Hoping I've captured the waveforms you were looking for, I've managed to clamp the fuel pipe enough to force it lean without completely stalling the engine.
During this period the pre-cat lambda seems to be switching like I would expect, post-cat still at a volt (Cat not up to temp?). S/T FT: -6% ~ -4% roughly.
Once I release the clamp it's straight up to 1V solid on both sensors and my S/T FT is -13%.
It was a schoolboy error on my behalf, when initially checking the MAF sensor I didn't read the idle voltage and compare to Autodata.
The L/T fuel trim was at -13 and when the new MAF was fitted it was a lower voltage therefore making it run much leaner and eventually brought the L/T fuel trim up to 0.