Twelve (12) Blinks on a 1988 Legend (auto trans) with 189,000 miles?

I've located the ECU and it is blinking 12 times, then stopping, then blinking 12 times, stopping again, etc.
If I am correct, twelve blinks pertains to a problem with the EGR.
What usually goes wrong with the EGR, how much does it cost to fix and is it servicable by a backyard mechanic?
The symptoms suddenly started a few weeks ago; rough idle and running, gas mileage under 15 MPG and a longer than usual time to warm-up.
Thanks again in advance,
njss396
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njss396 wrote:

Assuming that Acura trouble codes are similar to those of Honda-branded cars of the same period, it is an EGR fault. The most likely cause is carbon build-up in the EGR valve and/or passages.
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Look, please don't start new threads when you've already got one going. It breaks the continuity, making it difficult to Google for this stuff after the fact.
The error most likely means your EGR valve is stuck open due to carbon deposits. The ECU is reporting incorrect valve lift for conditions.
Disable (or remove) EGR valve and block hole. Does rough running go away? Then problem has been found.
I have crossposted this message to both groups you posted to. Please reply to this new thread only.
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