KA24E Emissions and Compression

[Souljourner]

Hey guys,

I just failed the emissions test on my S13 with KA24E. Although Chugz did his best to help out, I still managed to fail 3 times.

Most things are pass except two:

Driving N0x and driving CO.

CO is close to passing but just BARELY fails
NOx is almost double the required value.

When I leaned out the mixture by 10% using my S-AFC, the NOx numbers rises to 3 times the legal limit.

When I richen the mixture by 10% using the S-AFC, the NOx number rises to 4 times the legal limit.

So I’m stomped. The car runs fine now but just won’t pass etest.

The following are the states the car has gone through as far as I know:

0. passed e-test a little more than 1 year ago, and has new cat and new exhaust.
1. does not start, does not idle, came out of winter storage.
2. running without a working MAFS for 2 weeks (probably running very rich), fuel cutoff at 2500rpm and does not idle without throttle. Driven in this state for about 300 kms.
3. MAFS installed and car runs and idles good, compression reading 160, 180 180 160.

So guys, what do you think I should do now to pass the etest?

Any help at all will be greatly appreciated. Thanks so much!

[Jonweir]

Running rich for 2 weeks might have killed your O2 sensor. They are relatively cheap. Plus, if that happened recently, you might have to burn off your cat a little. Sounds to me that your cat could be gone though, it sounds like its had a rough time of it recently. You shouldn’t be having both a NOx and CO problem at the same time. You could always try blocking off part of your intake. That will reduce the air and with MAFs hence the fuel. You should get less emissions in general.

[Souljourner]

@philip_240sx

I failed on high NOx emissions. My problem is a clogged EGR system…

I have leaking valve guide oil seals = burning oil = clogged EGR system

The only way to fix it is to rebuild the head with new seals. I got a conditional instead… it was cheaper and I’m good for 2 yr’s.

BTW, bad valve guide oil seals won’t show up in a compression test. Does your car burn any oil???

Good luck… maybe you can find a shop that will tinker with the car a bit more and get it to pass?

Hey Phil, thanks for the reply! I’m gonna check to see if my car burns oil first… hmm

[oshiet]

Run with 10L of gas in the tank (gas light on), and pour in a 4L jug of denatured alchohol. It burns much cleaner and complete.

Make sure the cat is hot! My shitty SR passed this way.

[DarkForceJackal]

Yeah man, from my experience with emissions, run/check the basics: air filter, o2 sensor & cat (working & warmed up), EGR valve/system and maybe a fuel additive.

[MRWmotorsports]

Change your oil. After running really rich for 2 weeks it will be full of gas. Apparently clean oil makes the single biggest difference to e-test… apart from new cat

-Martin.

[Souljourner]

Ohh man thanks so much for all these ideas!

Where can someone buy denatured alcohol?

If I put 4 L of alcohol in the tank, do I have to adjust the timing differently?

[Sven]

Now I feel special. My car just came out of winter storage, crappy gas, old oil, drove it around for 10 and took it to the test.

Didn’t even come close to failing, most were 1/100th of allowed value.

[Pavel]

@Sven

Now I feel special. My car just came out of winter storage, crappy gas, old oil, drove it around for 10 and took it to the test.

Didn’t even come close to failing, most were 1/100th of allowed value.

aren’t you special.

[polex]

@Souljourner

Where can someone buy denatured alcohol?

If I put 4 L of alcohol in the tank, do I have to adjust the timing differently?

If you cheat with alcohol, MAKE SURE TO CHANGE THE OIL RIGHT AFTER THE TEST! The alcohol is thinner than regular gas, so it will actually go between the piston rings and cylinder wall and into the oil. I read that this is bad for some reason or another, but the reason escapes me… probably something about alcohol having a super-low boiling point.

[Sven]

@Pavel

aren’t you special.

That’s what I said isn’t it ? :slap: