this may be a pretty newish question, but why do some modern cars need to convert to obd2 even if getting a swap from a motor from the same year. (i.e. ek with 97+ h22a)

 

obd 2 cars don't take to modification as well as obd1 cars because they have more strict emissions and bullshit like that oh and btw a 97 would be obd1

 

You were almost corect on that, OBD2 was mandated to be in effect by 1996 by the goverment.

 

yea.. 92-95 is obd 1

 

i knew that

 

whats the best way to pass emissions then? my cousin used to tell me all this stuff but he moved to cali

 

does va do emissions? my car's never had to do it

 

depends on what part of virginia you are in

 

Go back to stock.....

Swapping a motor from OBD1 to OBD2 or vice versa may still pass the smog test. Is that legal? I dont know.... maybe from OBD2 to OBD1 is illegal. Of course, do not tell the inspector that you have an ECU that didnt originally come with the car. The single and most visible difference with these variables are the O2 sensors. If the car is originally OBD2 converted to OBD1, leave the secondary O2 sensor in place. OBD1 will not read it anyway. Putting a plug on there just raises questions. Remember, it's the modifications in the motor that makes the difference. Smog test is based off carbon monoxide contents. The more performance modifications you do, the more you are prone to failing a smog test.