NCT emissions failure advice?....

G

garethmac600

Petrolheads
Well I had the legacy in for its NCT today for the first time since the sti engine and ECU ( and everything else) went in to it, did better than expected and passed on everything except for the emissions, the fail results were:

-low idle Co2 1.07c (must be below 0.30c) FAIL
-high idle lambda : 1.08 (must be between 0.97-1.03) FAIL
-2710rpm Co2 0.13%vol ( must be below 0.20%) PASS

It has an old sport cat in it, which I don't have the most confidence in and is rattly so probably knackered, anyone know if these results would point to a shoddy CAT? Or is there another issue. Any advice appreciated!
 
Your lamba sensor is way out so have you need change that Sports cat should pass if everything else is good and it?s in good order . I?d start with the lamba
 
scoobysub said:
Your lamba sensor is way out so have you need change that Sports cat should pass if everything else is good and it?s in good order . I?d start with the lamba
Click to expand...

Just had a look on the laptop there with the Syvecs software and my lambda just after the turbo is reading 0.98, it's a brand new wideband (less then 500kms on it ) so I'd say it's good, but would I be right in saying their lambda reading at the nct is taken at the exhaust tip? As just looking now appears to be a slight blow in the flange of the sports cat aswel, so I'm thinking this is what's causing the very lean lambda reading out the exhaust tip? I'm open to correction here as emissions isnt my strong point :/
Sports cat is a bit of a vague fitment flange isnt perfectly lined up I'd say as it's a " custom" job.
 
If you have a leak before the Lambda it could cause issues.
Is the cat 100 cell or more ?
 
BazGF8 said:
If you have a leak before the Lambda it could cause issues.
Is the cat 100 cell or more ?
Click to expand...

400cell, it passed on my previous ver5 sti but since then it has developed a rather big rattle and one of the honeycomb structure inside it is just banging around loose. I'm not too happy with the fitment of it on this car though, don't think its fully sealing.
 
My 2c, might be a good time to look into replacing the sports cat. One option is to run a downpipe with a removable cat, which can be unbolted after nct. Should help with exhaust flow and spool. That's what I am planning to do on my car as its easier to swap in prior to nct rather than a normal decat downpipe.
If you're in Dublin, IceTronix can do that and that's where mine will be getting it done too [emoji106]

Subaru Impreza Wrx SL Wagon 2004
#hmblwgn
www.instagram.com/hhphoto7
 
hassen27 said:
My 2c, might be a good time to look into replacing the sports cat. One option is to run a downpipe with a removable cat, which can be unbolted after nct. Should help with exhaust flow and spool. That's what I am planning to do on my car as its easier to swap in prior to nct rather than a normal decat downpipe.
If you're in Dublin, IceTronix can do that and that's where mine will be getting it done too [emoji106]

Subaru Impreza Wrx SL Wagon 2004
#hmblwgn
www.instagram.com/hhphoto7
Click to expand...

Yeah I'm thinking the same, to be honest I was going to just try track down a standard legacy midpipe with cat, dont mind replacing the whole thing as i have access to a lift and garage so not a big deal to change over. I used a crowd here in cork (regretabley) wasn't happy with the welding or the fitment, they attempted a slot piece in the mid pipe but just didnt work well. I have a full straight pipe to go on after the nct that fits perfect so might try track down a midpipe and cat and see how it fairs on the retest.
 
With an STI engine swap, are you now running single turbo? My cat from MY99 STI has gotten a few things through NCT. Including legacy single turbo conversions.
 
You must log in or register to reply here.
Back
Top