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If i understood correctly p28 doesn't control egr.

is it possible to make it work with this ecu?

That's actually what PWM components are for... adding the EGR output. Available at most any retailer dealing with Honda Engine Management.

Will it control an actual EGR system? No.

thanks

Does a chipped P28 or P30 with a P72 rom operate the EGR or not? If not, is there any way to make it capable of doing that? Adding required components to the board or so?

the problem you are going to have (as was hinted above) is that there is a major difference between having an output to control the solenoid and having the software to be able to use it properly.
the first is easy, the later not so much.

Well, as I know, p72 operates EGR. Does a p72 ROM operate EGR in a p30 when added output circuit or not? It's the same question for the F22B1 SOHC VTEC ecu. (I'm not sure that an Accord rom works in a civic ecu or not)

And the next question is, how can I manage the way that the ecu controls the EGR?

If my memory is correct, the majority of that code was neutered or simply removed to prevent complications. One of the 'perks' of running the external rom.