Failed emissions NOx/HC help

[greasemunkey]

just had a magnaflow cat and resonator put on today, thought it might pass emissions, of course it didn't.
25/25 test
-hc - reading 00272 allowed 00160
-no - reading 03162 allowed 01179

50-15 test
-hc - reading 00260 allowed 00166
-no - reading 03327 allowed 01304

car doesn't have an egr system anymore, even the iacv has been ruled out. not sure what all was done previously, just was told the ecu was chipped by scotty. any suggestions on how to pass? I was reading to run high octane and retard the timing. no cel's brand new cat. drivetrain is a b18c1 and higher comp. pistons yeilding roughly 11.45:1 comp ratio, I also read higher compression creates higher nox levels. any helpful info would be greatly appreciated.

[superboost]

nox is usually created by heat so cooling your intake charge can help. You can do this by richening the mixture, but this may also bring up your HC and/or CO. You didn't fail by much, but without EGR, the nox will be a tad high. Water injection helps (if you're into rigging this up), as does running a bit of methanol or denatured alcohol through. Combustion chamber temps are probably too high.

[greasemunkey]

thanks i will look into those. now this might sound stupid but, if I turned fuel pressure down and retarded the timing could that solve the problem? less gas out the tailpipe and retarding the timing to run cooler right?

[Destineal]

Don't mean to thread jack, but care to run one day?

[KevinT707]

thanks i will look into those. now this might sound stupid but, if I turned fuel pressure down and retarded the timing could that solve the problem? less gas out the tailpipe and retarding the timing to run cooler right?
I do this EVERY year, I will get my emissions done without messing with my fuel pressure (42psi daily) and I will only pass like half the tests. I then come back another day and turn the fuel pressure down ALL the way and it pasts every single time. I'm currently running a Magnaflow high-flow cat. Of course I still have all my emission devices too though.

[Stuntman G]

Haha I beat your score . . . . my cat-less Supra did over 5k in both of the -no- tests lol

[greasemunkey]

retard that timing bro lol, unless your just reallly freaking high compression

[greasemunkey]

Don't mean to thread jack, but care to run one day?
depends, what ya runnin?

[RBS]

retard the dizzy timing. it will lower cylinder temps by alot

[greasemunkey]

but then i have more unburnt fuel :(

[greasemunkey]

im just going to advance it a bit and run 2 bottles of heet(methanol) on a half a tank

[afp6171]

get good SP wires(Accel) switch to E3 plugs and put your timing to factory spec. e3 plugs are provein to lower NO2/CO2 and add a few horse power. try it be astounded...

[RBS]

but then i have more unburnt fuel :(


retard it just for a few minutes, when your done with emissions you can go right back to where you were. ;)

[scttydb411]

just had a magnaflow cat and resonator put on today, thought it might pass emissions, of course it didn't.
25/25 test
-hc - reading 00272 allowed 00160
-no - reading 03162 allowed 01179

50-15 test
-hc - reading 00260 allowed 00166
-no - reading 03327 allowed 01304

car doesn't have an egr system anymore, even the iacv has been ruled out. not sure what all was done previously, just was told the ecu was chipped by scotty. any suggestions on how to pass? I was reading to run high octane and retard the timing. no cel's brand new cat. drivetrain is a b18c1 and higher comp. pistons yeilding roughly 11.45:1 comp ratio, I also read higher compression creates higher nox levels. any helpful info would be greatly appreciated.

did i just chip it, or did i also dynotune it? o2 sensor enabled/working? try running the car for a while on the highway to really heat up the cat. mark the dist and retard it all the way. go pass. of course if i just chipped it w/ a basemap then it needs to be tuned first otherwise you'll probably be wasting your time.

[greasemunkey]

no o2 it has been ruled out of the ecu, i do not know what was all done tuning wise, I was just told chipped

[AnthonyF]

I can help if you aren't looking to fix. PM me.

-Ant.

[scttydb411]

no o2 it has been ruled out of the ecu, i do not know what was all done tuning wise, I was just told chipped

if not tuned then higher likelyhood it'll fail. o2 deleted w/ increase chances of failing since the emissions test takes an average reading of the ecu correcting rich/lean. you could possibly pass w/ the steps you're taking and possibly pulling the timing all the way back.