Here's whats up: My brother has a 99 canadian Si coupe with a d16y8. It chucked a rod, and we swapped in another y8. It had a vacuum leak around the intake manifold gasket, but that was replaced with a brand new OEM gasket, but it is still having idle issues. I have cleaned/exchanged the IACV twice. I pulled the codes and it is reading primary 02 heater, IACV, and a missfire on all 4 cyl's. But the engine seems to run smooth, other than the idle issue. The idle either has the usual honda 1k-3k bounce, or a 1400-1600 quick bounce which I have never encountered before. Has anyone ever had an o2 sensor make a weird idle? Also any ideas as to why it would be throwing codes 71,72,73,74 at the same time?

 

did you try swapping the crank positioning sensor over from the other motor ? this is the sensor that throws these codes. its down by the crank under the timing cover by the crank. or maybe swap distributors.

 

Or bypass the sensor altogether.
http://www.google.com/search?q=ckf+b...ient=firefox-a

 

If you reset the ECU and drive the car, do all or some of those CEL codes repeat? There's no reason to waste time chasing codes that don't repeat.

 

I reset the ECU, and no code's as of yet. But it doesn't get drivin any more than around the yard as of yet (not licensed). It still idle's like hell though.

 

Have somebody else drive the car around for 20 minutes to see whether any CEL codes return.

 

thats what I plan on doing this weekend when I get a chance. Don't have a whole lot of spare time left with college and work and all that good stuff.