Failed emissions test, the other day.

MN12 KID

Registered User
According to the dyno, I was pushing out a NOx level of 542, out of a legal 220. I'm in NY, and they just lowered the emissions limit.

The passengerside cat is rattling a little, when I'm on the throttle. I'm thinking that's the issue. I have a warranty at Meineke - perhaps, the car will pass, after the replacement.

Is there anything else I should consider, before re-taking the emissions test?
 
High NOX readings indicate an elevated temp in one or more combustion chambers. Things that can cause that are.
1. Lean condition in 1 or more cylinder.
2. EGR acting up.
3. Ceramic coated combustion chambers and not properly tuning for them.
4. Dead cat.
 
Well, I'm looking towards running lean, or a dead cat. My car has no EGR.

I'm going to get a fuel pressure tester, tomorrow - I've been getting check engine lights on and off, when I'm on the highway for a while. I pulled a lean code on the left side, so anything's possible there - o2 sensor or injector? I'm going to change the fuel filter, too. Plus, I got a code for a weak #1 cylinder. I'm hoping it's something simple, like an injector - better not be the damn piston rings. :(

Basically, I'm going to change the fuel filter, PCV valve, and cat, hoping for the best. If (big IF) I'm still failing, I'm gonna investigate further into the matter, starting with the injectors. If the rings are shot, I'm probably going to look into my spare block and have that rebuilt, and do the swap.

Wish me luck!
 
What do you mean you got a code for weak #1 cylinder?
What test gave you the code?
What was the code #?
 
Solution

I had ran 450'ish NOX and changed one 02 sensor - driver side was indicating lean steady with no switching - watched it with a scope - brought nox down almost to pass and improved idle.
HOWEVER - if you really want to drop NOX and have lots of room on the other tests, pull the octane adjust plug - this knocks 3 dgrees off the full timing curve, I got Nox down to 126 doing this
Good Luck
 
Okay, Meineke says the cats are fine - what else should I look into, now? My inspection is over a month passed due. Help, please! :(
 
i say u pay the SMOG guy under the table... if u know what i mean... how do u think i got the plates for my SC



shhhh but dont tell no one... seriously though
 
make sure it is good and warm over 200 i used cardboard in front of the rad ,check air filter , 92 hi octane fuel, maybe 02 sensors , or spray throttle body with cleaner or , put some gumout injector cleaner in the gas , loose spark plug ?tune up plugs or wires check vacuum hoses i used cable ties as clamps on vacuum hoses for more boost on mine
 
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I'd take it to a place with a diagnostic scope. They should check the injector signals to make sure they are correct. Thus if you are having a balance test show a weak injector, you know it's the injector rather than the wiring.

If you have never replaced your oxygen sensors, that would also be something to try.

But first, if you feel confident in a #1 cylinder fail the balance test, you'll want to get that fixed first. If it's more serious than just an injector, you can probably get a waiver for this year.
 
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