Actually I don't know much of anything about egr on either car. I just found a little bit of info: http://www.hondacivicforum.com/m_233933/tm.htm including one guy who says it's only on automatics. I will have to take a look at my hx later.

Doesn't the 88 have that weird passive rear wheel steering thing?

Will a d16y8 transmission work? (edit: nm, forgot about cable/hydro)

Also, as for my goals with this -- I am looking basically for a balance of mpg and power. I like getting 30/40mpg city/hwy in my HX, but I like CRX's more than Civics, so I figure this would be an even better combination.

According to my half-ass calculations, assuming the HX is 2500lbs and the CRX is 1800lbs, and the y5 makes 115hp, then the 700 fewer lbs is roughly equivalent to increasing the hp on the HX to 160. I basically calculated each car's "hp per 2500lbs" with the y5:

(115 / 2500) x 2500 = 115
(115 / 1800) x 2500 = 160

I wonder what effect it will have on mpg...