failed smog test
 

i barley passed the one at 2500 it is like 138-140 hc but when it is at idle it just starts going up to like 800 or 900 hc on time it said 1500 hc but this was at idle what can be making the numbers go up so high at idle this is a s5 na it also has s4 engine with the s5 computer and intake can it be injectors i put a different acv in it and it was about the same i thinking about putting alcohol to see if it will help any ideas what it can be

i think you'll need to match the ecu with the right engine, so if you have an s4 engine, you need an s4 ecu

i found a vacuum leak from the egr block off plate i made but will that mess with smog testing

Actually, vac leaks tend to lower numbers, due to unmetered air being allowed into the engine. I think your issue is your S4 engine in your S5 car (can I ask..WHY?) .

i crashed my s4 car and i was able to find a s5 that needed a engine and tranny

Are you using the S5 upper and lower intakes/throttle bodies? My guess is that your not..

yes i a using the intakes ,afm,omp,tb with the tps

Well, what you have effectively done is mix a non-EGR type intake system with an EGR type motor. I could go into all kinds of reasons why you are failing, but all that matters is, your intake path isnt getting diuted by recirculated exhaust gasses. So your only option on passing emissions is....CHEAT!

This is exactly the same problem I am having with an S5 motor in an S4 car. And I have learned a lesson from all this...

If you live in an emissions state, dont mix motor series.

Jarrett

if i don't have the bac hooked up will it mess with my smog test numbers