Engine ECU.

Hi all.

I have a couple of problems with my 03 Rx4 dci. All electrical and all engine oriented. ( No rev counter, Runs very bad when MAF is connected.)

I have changed tdc sensor, dash clocks and MAF. But the problems remain.

I thought maybe it could be a dodgy ECU??

Now, my question is, if I get one from a breakers, will it just plug and play, or will it need coding ro my vehicle?