We've not long put a bigger/better engine into our 93 EG Honda Civic (b20 bottom b16a head with a t3t4 turb fully forged internals etc etc) we haven't got it tuned yet coz we still need to do a few more things to the engine before we chuck her on the dyno, what are the cons to driving it untuned? It's been running for about 2 months now & we've been driving it this whole time. It seems to be driving okay for it's current condition except when it goes over 4k rpm the check engine light comes on & it runs like **** but does anyone have any advice? Should/shouldn't drive it? Major issues from driving it? Anything?