98ektypeRhatch

im haveing trouble with my car i had a good running b16 in it i took it out of my car and put a gsr in it and and now its throwing code 21 and 41 and at idle its surging real bad i changed the iac valuve and it has a lil air leak on the throttle body gasket im trying to figure out why it is surging at low idle?

wright

So, 21 is Vtec solenoid. Most likely you do not have it hooked up correctly. 41 is the O2 sensor. The main thing that you need to fix is the air leak on the TB gasket. Just so you know there is two different gaskets so take the TB to the parts store to make sure you get the correct one.

LoveMyLS

vacuum leak will cause surging. vtec code shouldn't cause surging. are you using the engine bay harness from gsr?