PR4 comes in two flavors; 90-91 OBD0 and 92-93 OBD1. They are all chippable.

If the crower valve train (and cams, right?) claim 8K revlimit, I'd have no problems chipping for that. You'll have improved the stock LS flat spot in power output between 6-7K, but if the head wasn't at least mildly ported there are good gains yet to be made in that area.

Jason knows what he is doing, and so far has given you excellent advice.

 

there are actually 3 different PR4 ECUs.
-OBD1 92-93 PR4 (recognizable by OBD1)
-PR4 w/ internal PA sensor (I think these are 91)
-PR4 w/ external PA sensor (I think these are 90)

Only reason I bring this up is that you will have a CONSTANT Code 13 if you put external PA code in a ECU with an internal PA sensor.

I have both internal and external PA PR4s sitting around pre-chipped, I would be more than willing to sell you one on a core-replacement basis so your car isn't down. If interested email me.

 

hey, i'm kinda new at this what is the diff between in & out pa and code 13 the car runs excel now just that when i had a friends ecu from a zc it seem to produced better and pull harder at 8000 how much with trade. i"m waiting to here from 88crxsi with some ?'s thanx mark

 

those three guys (Joseph Davis, Blundar, and TurboEF9) are more capable of help you out here.

But as you stated in your PM, you have stock cams. Don't count on gaining much past the stock LS motor's rev limit w/o matching cams to the crower valve train.

 

PA sensor - http://www.nitroburn.com/pgmfiwiki/i...sureAtmosphere

Code 13: the error code (1 long, 3 short or 13 short) that the ECU generates for a bad PA sensor.

This http://www.nitroburn.com/pgmfiwiki/index.php/PR4 will help you identify whether you have a PR4 w/ internal or external PA sensor. Look at your stock ECU for this. I'd bet money you have one without the PA sensor, as in the first 3 pictures on that page.

Let me know which kind you have. I'd sell you a chipped PR4 that is the appropriate type for $50+shipping and your original PR4 as a core.