Lambda causing MAF 00553 Code? Anyone else ever?

[Colesy]

After a long drawn out fault finding saga where my ABY would stall when stopping I've finally fixed it.

The problem was when the car was up to temperature and I came to stop at a junction as soon as I dipped the clutch the rev's dived to 0 causing a stall. I could prevent the stall by feathering the throttle but this wasn't much fun...

I had the fault code 00553 which indicates the MAF. So after a long drawn out search managed to get a new MAF (Thanks Ben!). I fitted this expecting everything to be sorted and on my next long trip the exact problem was back with avengence.

So I systematically changed many parts, but what finally fixed this was to swap the fairly new Lambda sensor for the old one I removed last year. I was given this idea by a thread on here that I can't find any more. I've been told that the Lambda shouldn't cause this code. But I thought I'd see if anyone else had seen this before?

[prj]

There is one thing I can think of - shorting on the lambda heater, and causing a voltage drop in the 12V supply, making the MAF also under read at the same time.
But to be honest, I'd expect the fuse to blow then.

[Colesy]

There is one thing I can think of - shorting on the lambda heater, and causing a voltage drop in the 12V supply, making the MAF also under read at the same time.
But to be honest, I'd expect the fuse to blow then.

The Lambda fuse did blow once right at the start of all these problems, I suppose you'd expect it to keep blowing though wouldn't you?

[prj]

Yeah I'd expect it to keep blowing.
As I said, that's the only explanation I can find. ECU gives signal too low code when the MAF read value is either basically zero or below a certain range and RPM and throttle position above a certain range.

I had to disassemble and modify the diagnosis completely to accommodate my speed density and big MAF conversions, as they would otherwise throw codes all the time.

My best guess is on O2 heater shorts causing voltage drops/spikes...

[Thecrispynoodle]

I found troubleshooting air/fuel at idle issues to be a real lottery, different DTCs being thrown all the time and 561 being the only consistent one. Ended up replacing O2 sensor, TPS, ISV before discovering it was the 034 motorsport billet PCV valve causing the issue. Swapped it back for original and problems went away. No more 561s