Ok fellas so i got a 2000 civic si acouple months ago im finally getting the time to work on it and i just keep coming across MORE AND MORE stuff thats just rigged all i no about the car is its still a b16 but isnt the stock bottom end, The person that had it before me converted it to obd1, it has a p28 ecu in it now and vtec dosnt even work, theres plugges from the harness just hanging in the engine bay not even connected to anything, so i guess after all thats said how the F@$( do i get it back to obd2! thanks for the help

 

The first item you need to return to OBD2 is the stock P2T ECU.

 

Thats the direction im goin but all my egr and purge valve stuff is missing once i got p2t its gonna run like crap huh

 

What I would do is leave obd1. It must have been done that for chipping purposes obviously. What you can do is find out what all the extra plugs are to and then figure out why vtec is not engaging. If the plugs are to things like CKF and the EGR and purge valve you are okay because obd1 does not have those sensors. Your other optino would be to return it to stock by reconnecting all the plugs and putting stock ecu back.

 

ok so i checked my codes for my cel today and its showing 17 and 19 and still no vtec i pulled off the seloniod and the pressure valve everything is gettin oil. what should i check next and why would (19) come up with (automatic trans lock up controll valve? this car is a real si as far as i no all vins say em1, all help appritiated thanks the ecu says 3782-p28-a52 761-763135

 

you have an automatic obd1 ecu. is it chipped?

code 17 is vss.

 

suposidly it is chipped... im not 100% certain. how can i tell?

 

You need to convert it to manual. You will throw that code if you use it with manual car. Or get the p2t ecu and convert back to obd2 which might be more work. There is an entire thread on here that tells you the step by step process of diagnosing no vtec. https://honda-tech.com/forums/honda-prelude-4/official-%22why-vtec-doesnt-engage%22-thread-830163/

 

would being automatic ecu mess with vtec? thanks for the link

 

Not that I know of. Convert it and re chip it or get the correct ecu and go from there. Who knows what the person had done to that ecu.

 

The VSS CEL is why vtec is not engaging.

 

right i hate buying rigged cars but the em1 is my dream car and i got if for $2000 so i guess its whatever, but i did have the car on the lift all day yesterday and found a nice dent in the oil pan, figured it wouldnt hurt to hammer out, my oil light used to come on at real low rpms like 600 but now that i hammerd it out i havnt seen the oil light since. to bad that wasnt the complete problem, gotta order the vss and see what happens. i actually pulled the vss yesterday to but the gear wasnt stripped out or nothing, guess the sensor is self is just bad as i have no speedo or odometer thanks for your help again guys

 

Before you go replacing the VSS, check the wiring for it. I believe there's a how-to in the FAQs.