NJ state emissions Failed at idle ONLY

[obracer12]

ok I have done a few things to get my swapped car to pass, but can't pass idle emissions. A few things I know that might help.

1) I'm 2k miles past an oil change... so I need to change it to get my ppm down (pvc screwing me)
2) have a cell for knock sensor.. but have passed with it on before

Car = 92 SI hatch with B16b swap to a P73 OBD1 ECU
-cam BC stage2
-valves BC
-Short ram
- 4-1 + test pipe + full 2.5" exhaust

Readings:

Mode: Idle - fail
HC ppm reading 464 standard 220 FAIL
co% reading 0.53 standard 1.2
Co2% reading 14.1
O2% 1.6

Mode: high idle - pass
HC PPM reading 122 Standard 220 PASS
co%0.92 Standard 1.2
co2% 14.2
o2% 1.0


Thoughts?

I was thinking of throwing a 1/4 tank of 93 in it and 1 qt of denatured alcohol in it and go for just the idle test being that this is the initial test AFTER an oil change. Maybe sprat out the IACV screen with some carb cleaner?

I know it isn't a huge fail (especially with the swap)

Any ideas? Ron? c'mon buddy I know you got something in you for this minor PPM change.

 

[92lseg]

Tank of 93... Your running a b16b and not feeding it 93?

 

[obracer12]

feeding it 91.. easier to get by me

 

[RonJ]

1) Fix the KS CEL.

2) The O2 reading at idle and high idle is unexpectedly high. Check for an exhaust leak near or upstream of the primary O2 sensor.

 

[obracer12]

1) Fix the KS CEL.

2) The O2 reading at idle and high idle is unexpectedly high. Check for an exhaust leak near or upstream of the primary O2 sensor.

1) ok... lol
2) the O2 sensor is at the collector flange of the exhaust manifold. All parts are new manifold to tail pipe.

 

[Jermee]

I live in Louisiana where they don't do emissions. How would they know if you didn't do the emissions testing?




Sent from your moms house.

 

[RonJ]

2) the O2 sensor is at the collector flange of the exhaust manifold. All parts are new manifold to tail pipe.

Regardless, the high O2 readings tell you that there's outside air entering the exhaust system near or upstream of the primary O2 sensor. This leak would cause the engine to run rich.

And why would you ignore a KS CEL, or any CEL for that matter?

 

[obracer12]

Regardless, the high O2 readings tell you that there's outside air entering the exhaust system near or upstream of the primary O2 sensor. This leak would cause the engine to run rich.

And why would you ignore a KS CEL, or any CEL for that matter?

ks cell was ignored due to the car sitting for about 3 years and finally getting it on the road. also I neglected to recognize the harness is lacking a knock plug... which I now have to source... and only comes on once the second fan cycle starts... barely ever in the car that long to notice.

Chances are the ks cel repair will fix it to be honest... or to at least drop the rich condition.

Will do a leak test on/prior to the O2 sensor. If there isn't a leak would a loop cause this same issue?

Jermee : we have obnoxiously colored stickers on our car that have the month/year of last inspection. Law enforcement in this area pray on anyone even 24 hours out of date. If you fail you have a bright red "rejected" sticker on your car.

 

[obracer12]

update:
Pulled all codes and fixed accordingly
KS - Used a second harness IATB plug minus ground to fit and re-wire to pin D3 on the ECU = cel eliminated
Oil pressure sensor - wire rubbed through on the alternator bracket. patched/heat shrunk = cel eliminated
Reset ECU = no CEL

changing oil when this monsoon passes and going for a re-test with a bottle of heet for good measure.

 

[obracer12]

retest after fixing cel codes, still need an oil change and may put in an additive to retest:
Readings:

Mode: Idle - fail
HC ppm reading 282 standard 220 FAIL
co% reading 0.53 standard 1.2
Co2% reading 14.1
O2% 1.6

Mode: high idle - pass
HC PPM reading 122 Standard 220 PASS
co%0.92 Standard 1.2
co2% 14.2
o2% 1.0

 

[RonJ]

...the high O2 readings tell you that there's outside air entering the exhaust system near or upstream of the primary O2 sensor. This leak would cause the engine to run rich.

 

[obracer12]

Ron ran a check on all gaskets and removed an added anti-sieze sealer to the O2 sensor/ bung. Did the back of the hand test at all joins in the system, the exhaust system is not leaking at the time of the test.

Cleaned O2 with maf sensor cleaner. I find it highly unlikely with the change in ppm from last test to this one that the O2 readings would be identical too...

Could there be a secondary cause to this reading?

Changed my oil today and will retest either this week I I get out of work early or on Saturday morning.

 

[RonJ]

When the engine is running on the rich side and O2 levels are high, there's an exhaust leak. Have you checked the entire exhaust system?

Is the O2 sensor plugged into the header? Have you checked for cracks or a bad exhaust manifold gasket.

 

[obracer12]

I did check the system. Replaced the system, exhaust manifold an gasket 3-4 weeks ago. Torqued all bolts to spec. I did not use a liquid sealer in addition to the provided combination gaskets.

Reused the old O2 sensor and put it in the bung dry, but today while doing oil decided to check the bolts and put anti- seize on the O2 threads. The sensor is on the cylinder 3 runner 2.5" from the collector flange. This is where I suspected a leak by was unable to find one at the collector.

Did not see,feel or hear any exhaust leaks. At this point I believe it may be that my failure (60 ppm) is due to the b16b in a d16z6 equipped body... Though I thought their idle fuel curves are very similar.