Hello All!

My first post in this excellent forum, I trust the expertise of some users can help me with a problem I cannot solve.
Summary:
swapped 1990 original engine with a 1996 JDM engine.
Changed downpipes and removed cats.
Eliminated IAV

Car started and run OK, but heavy fuel smell off the exhausts. Replaced cats and improved, but not good.
Error 12 MAF. Tried 4 different MAFs, 3 new. No good.
RPM counter on meter panel no signal (both on original EU panel and Japan OEM panel...).
Checked there is no signal from ECU back to MAF (!)...

What can be the cause and how can I solve it? I am at the end of my tether...

Thanks in advance for any good advice.

What ECU are you running? the 96 engine has many sensors that differ from the 90 because of the OBDII system.