Car didn't pass emissions - high NOx readings

[Ludachris]

From what I've read, I need to check my EGR valve and try replacing the spark plugs. Joy. In Colorado, it's the seller's responsibility to get the car tested. I wrongly trusted the guy to bring me a valid certificate, he didn't. If this costs me anything significant, I'm taking him to small claims court.

 

[TJCTalon]

Tell me about it luda! My last dsm wouldnt pass emissions and the seller promised it would. I almost took him to court but it wasnt worth the hassle.

Anywho usually high nox means your leaning out.

This helped me out maybe it will do you some good

Failed Emissions? Check here.

 

[Ludachris]

Well, the car doesn't have any tuning devices attached, so I'm hoping it's just the base timing - I've changed plugs and will check the timing before I mess with the EGR valve. I'm still getting a Cam Position Sensor circuit malfunction CEL code, so I suppose that could be part of it too.

 

[RoasT BeeF]

Have you checked for vacuum leaks Chris? I'm sure you know high nox is a result of high combustion chamber temps pure and simple. Any un-metered air entry can contribute to this. You are on the right track with the EGR and ignition timing as well. It may be a bit to far advanced.

Did you ever determine if the car has a 6-bolt head?

 

[Ludachris]

Have you checked for vacuum leaks Chris? I'm sure you know high nox is a result of high combustion chamber temps pure and simple. Any un-metered air entry can contribute to this. You are on the right track with the EGR and ignition timing as well. It may be a bit to far advanced.

Did you ever determine if the car has a 6-bolt head?

Yeah, I'll check for leaks as well. I haven't looked into whether it's a 6-bolt head yet.

 

[DSMDEMON93]

I would check your Catalytic converter. When my turbo blew, all the oil blowby clogged it so bad, I fail smog by DOUBLE the amount of NOx, and high levels of HC as well.

 

[DSM1G90]

..what I was wondering ... those bricks in the CAT could be all coated up and can't do the job too well ...

 

[lcrivers816]

what happened?

 

[Ludachris]

Haven't gone back for the 3rd test yet. The second test failed both HC and NOx, by a higher margin - but all I did was replace the plugs and tighten up some bad boost leaks, though the FMIC core was leaking quite a bit. I just finished up replacing the FMIC, and will check the EGR valve before I test it again. I really wish I would have not paid the guy before I got the emissions cert. Anyone know if I have a case to take him to court? .

 

[DSM1G90]

How I failed the HC test on my first test was rather embarrassing: had a pan of dirty, smelly oil which is full of HC in itself due to loading up with moisture, rich mixture starts and numerous stop and go in-town driving being that I'm a DD, along with motor tolerances a bit on the loose side where I'm only getting 1200 miles to a quart.

PCV valve was sucking in some of that HC to really shoot the readings high.

I did have a dirty EGR valve which I cleaned out, fixed up turbo intake leaks, and got my timing back to specs since it did slip to retard, along with replacing the O2 sensor which was getting very lazy and weak at times.

Thus, with a tip from an emissions tester was to change the oil right before the test..in which I did with making sure the most of that stinky oil was gone by letting it drain out of the pan for a good hour along with letting it run out of the oil filter fitting area before capping the two areas off with filter and the drain plug.

From a HC count of 1475ppm on the first test down to 178ppm on the sniff with the state's limit at 220ppm, I passed HC on the idle test in flying colors. My CO and NOx test came out good meaning a good cat was in store.

Filled it up with Mobil1 10w/30, got it super hot on a freeway run then headed to the sniff place to get my passing grade for two years ...

Good luck-DSM

 

[Ludachris]

So just wanted to add to this thread - I just finally got the car tested/passed and registered yesterday.

I cleaned out the EGR really good and replaced the O2 sensors with some used one from a friend. It finally passed, after 3 tests. Third time is a charm I guess. Now I can drive the car without expired temporary tags!

 

[dsmvenge]

I failed too after being promised it would pass. P1105 and a random p0100 changed both the fuel pressure solenoid and the maf cleared and came back starting to think my ecu is bad. Was promised the car didnt need a motor either but hey i got 200 miles out of it before I had to buy a new one. And imagine this still fails emmissions, Rollin a expried temp tag

 

[ed1380]

you guys are lucky that you at least get temp tags. my county is stupid. No temp tags for any reason. "tag applied for" and hope you dont get pulled over

 

['97boostinGST]

I got reffed and had to get the car smogged.
It failed so bad it on Nox and HC that it was considered a "Gross Polluter"

Second time, i changed spark plugs, cat and oil right before the test.
Numbers went WAY down and only failed NOx and also failed because apparently my friends cat is for a Ford E-150 V8 van.
Compression on cylinder #3 is at 90 so im assuming its my low compression thats killing me.

 

[Ludachris]

you guys are lucky that you at least get temp tags. my county is stupid. No temp tags for any reason. "tag applied for" and hope you dont get pulled over

I got two 10 day extensions and then I was driving it for a month hoping not to get pulled over. Then I was able to park it for a few months after the job change at the beginning of Feb. Just now got around to fixing the problem.

 

[DSM1G90]

I even heard that blocking off he EGR actually helps in HC readings since it's not reburning the junk vapors from the exhaust...wonder if that is so...

..and wonder if catch cans would aid in lowering HC emissions as well ...