Outer Limits 4x4 Board

May seem like a slly question but how often should a dyno need to be done ?
TD42 is Starting to be very "flat" between 1900 and 2300 rpm

Most cars never see a Dyno and it will only tell you what you already know.

I would look at
new fuel filter
new air filter
check for blockages etc

Then maybe
Injectors serviced or the Pump looked at


Probably doesn't have a catalytic convertor does it? But if so maybe check it's not blocked too.

in 2nd, 3rd gear?? fuel pump filter!!!!

The dyno will tell you alot.

Is it a fuel starvation problem or air restriction? Shows up very quickly when measuring AFR.

Poor injector atomisation often shows up with big spikes in the afr as the bad cylinder/s dont burn the fuel well