sup guys just wondering ive heard multiple sides to this but anyways i have D15B it originally came with the smaller intake manifold and from what i understand are 180cc or 140cc injectors? and i swapped it over to A Z6 manifold with mateing Z6 injectors whic i belive are 240cc? any ways, i have an emmisions test and i figured better be safe then sorry so i put the smaller injectors thinking it will help lower emmisions and there mated with the Z6 manifold but now that their on the bigger manifold i occasionally get a cel saying fuel supply and o2 so im thinking that there not able to support with the Z6, as if their to small or somthing like that. so ima put the Z6 injectors back on but was curious as to if it would make my emmisions worse or not?

 

you cant just swap different size injectors and expect it to run right without a tune

 

@doood well yes i get that part lol when i swapped over to the Z6 manifold and injectors the car ran great really well but then when i put the smaller injectors thats when i started seeing problems

 

You need the z6 injectors if you're gonna run the z6 manifold, " i swapped it over to A Z6 manifold with mateing Z6 injectors , more air needs more fuel or you'll run lean(<<<you probably already know that).Which will most likely cause high NOx in your emissions reading.

But if you're putting the injectors back on you should be ok. Post up a picture of your emissions, if failed and I can imput more on this. )

 

ok and yea i got high nox on my test i passed 25 and 35 mph test but ifailed 15 but not alot lol and this was with th smaller injectors with the Z6 manifold but ill take a pic of my sheet so you can see it

 

hes a pic of my test

 

also my car has aem cold air wich is carb legal but will it help to just take it off and put stock one? in the test results shown above i had AEM carb legal with the smaller injectors will it help to put stock air box if so ill go borrow one?

 

that looks like you need a cat. co is high and nox is high. that means cat time. co2 is at 14.7 which shows the car is running efficiently. not perfect but efficient.

 

forsure its impossible to find one lol

 

bump

 

so what have you actually done to remedy the situation? or are you just hoping it will magically fix itself through peoples suggestions and opinions?

 

for starters i put the right injectors on and reset the ecu and it happend again and my main relay goes crazy i have to disconnect the realay harnes and put it back in while i turn the key to on continously untill i hear the fuel pump kicks on and then its all good

 

The first thing I would do with high NOX is to clean out the egr valve and ports. If it still fails then I would go the cat route. Given that the cat isn't able to catalyst at the 25 mph level it would appear it is bad, but still. It's cheaper to clean out the egr than to replace the cat.