failed smog Options

[LewFX]

my week cant get any more crappier so why not throw in a failed smog check while im at it...first test was horrible due to no cat headers! okay so i put stock manifold back on, failed by 60 points on the 15mph. the guy thinks the egr solenoid is bad.

[alltracman78]

Sorry man.
I don't always remember all the posts I answer.

If you want to skip my babbling, just go to the line of stars.
My babbling is me trying to help you understand this so you can make an educated decision next time.

You had no CEL?
It's possible it is something in the EGR, but it should have thrown a code...
I hope it is that. Do you mean the EGR valve itself?

Here's the skinny.
NOx is caused by high combustion temps.
Exhaust gas put back into the comb chamber lowers the temps because it takes up space oxygen would otherwise take up. Less oxygen, less fuel, less boom.
So, alot of the time when there's too much NOx in the exhaust, it's a faulty EGR system.
However, there are other things that raise combustion temps, causing alot of NOx to form.
Lean fuel mix
Higher compression [think carbon on the piston, raising the C:R]
Inefficient cooling system [not necessarily overheating, just hotter than normal]
High engine load [EG accelerating in 5th gear @ 25 MPH]
Advanced ignition timing

This is why it's important to have your COMPLETE car working well, especially when you go to the sniffer.

Here's a good example of this.
My truck
Where I live we also go by Ca emissions as far as the sniffer goes. Dyno and all.
We just get tested every 2 years.
I had just moved back up here, and had to finally get my truck inspected.
I had just rebuilt the engine ~ 17000 miles before.
I had disabled my airpump, welded shut my EGR valve, and punched out my cat. So I had absolutely zero emissions equipment working on it [I am in the process of changing back to them. I didn't totally understand at the time how they worked, and I don't have a 1000 HP race truck, so I see no need to pollute...].

With absolutely no emissions equipment working, I passed the sniffer.
My CO and NOx were WELL below the limits.
My HC was very close [like .3 PPM below], but my truck is carbed and has a high duration cam, which basically means you have to run REALLY rich at idle.

Your engine [and car], both to pass the sniffer easier, and to run better overall, should have regular fuel injection services, coolant flushes, trans flushes, and even brake and pwr steering flushes. Mostly OT, but I thought I'd add it in here.

I hate to recommend this to people, because alot of it costs a good chunk of change, which some folks can't afford. And your car will get by [in some cases for a very long time] without doing any of it.
But it's better to do it.

To clean out your engine you can try Seafoam first, but it doesn't work as well as a real fuel injection service. Nothing wrong with Seafoam, BTW, I love the stuff.
But sucking it [or any cleaner] through a vacuum hose as compared to a service where they spray it in you engine, run more though your fuel line [no fuel, only cleaner], and drop a can into your gas tank is like comparing how well a carburettor mixes fuel/air to how well injectors mix fuel/air....

I think that's all.
I'm sick of typing.
If I think of anything else, I'll come back and add it in.



****************************************************

SO, if that EGR valve doesn't fix it, I would recommend getting a GOOD fuel injection service [it will unfortunately cost you...], and possibly a GOOD coolant flush.
Check your ignition timing while you're at it.