Hello i have a tuned alfa 1.9jtd 140hp. Egr is off en fuly decatt. Above 3800rpm i have a overboost problem. What is wrong.

The duration of fuel delivery, from 50mm3, + 25%. This will result in an imbalance in the N75. But N75 is 10% with 50mm3, which helps a little

I take a look later,do you change turbo error code??

Sorry to dig up an old post.

But this is to warn Alfa owners, when they totally decat quite often they get turbo creep.

Which induces a limp mode.
Leave your cat in place, the turbo needs that back pressure.

My 2 cents.

you dont have boost creep in a remap decatted jtd 16v if you know how to tune vnt maps

I agree with you Jtdpow, but how many do it?

There is a bit of testing before getting it right.

Is it necessary for a road going car? I doubt it.