OK. I installed my hi-6 w/ tach adapters a while back and got CEL's, but haven't called Howell about it until today.

My understanding of the function of the tach adapter was that it kept the ECU from seeing any problems and therefore, no CEL. The guy I talked to at howell told me that's not true and that even with the tach adapters I should still get a CEL and that I needed to buy at $190 trigger box to eliminate this. Is that correct?

I believe them, but my impression the whole time was that the tach adapters solved this problem...

Thanks,
Matt

most ignition systems run off of single coil systems. which is what most honda's have. we have a dual coil system so we have to have tach adapters to synchronize the sparks. hope that helps you out.
later

That's how I understood it should work. I just put mine in since the engine was out, I'll post if the code goes away once I get it up and running again.

Do you guys all have 2 tach adapters for your Crane? When I ordered mine from Howell, they told me that since I was a 95, I needed two of them. I haven't put the ignition in yet(will be in about 2 weeks), but I think I also need a new MAP sensor as well....

yes, 2 tach adapters were needed. I believe the trigger box that I talked about above should replace both of them, but it's quite a bit more expensive. You'll need a separate MAP sensor if you plan to run timing retard per boost, but otherwise you shouldn't (unless yours is busted)