well that's actually what's been going wrong for me and throwing me a curve ball as the Americans say.
I ordered a genuine Bosch F00C 2G2 044 from driven2automotive on Ebay. They sent me part F00C 2G2 030 suggesting it was compatible. but i already had a 030 that I bought from a 5 time Alfa owner on Gumtree for £25.
I tried it, but it has a flat spot after 3000rpm. It looked new, so assumed it was because he told me it was.
However, I tried unplugging it, and it didn't necessarily run better, but did have more raw grunt, and the computer showed improved mpg as I only average 30 and live in a town surrounded by 60 mph roads.
Then I read the MAF data base and it was said that SOME JTD's up to 2000 could use 030 or 033 as well as 044. But below that my model, 150hp 10v was 044 specifically. So I contacted the bosch supplier who were adamant that they knew what they were talking about, and would send out part 044 after i returned it. I just cancelled the order for a full refund until I can find out for sure if what they claim is true; that I can use 030.
If it's true, then there is something else up with the car, if it's not true, no wonder it still doesn't run right.
To make it all more confusing, It hasn't suffered the turbo lag on stopping while using 030, but flat spot at 3000rpm.
Today i found a used 044 and put that on, but then turbo lag after driving and slowing down, untill 3000rpm then it takes off again.
I'm bloody exhausted!!!
So, at the minute I have another 044 on, producing the same symptoms as the original.
Macbeast suggested turbo stuck in boost position, so I need to look at that next.
At this point I'm lucky i didn't pull out for a £91 MAF!