How to reduce Nox emissions???

[Frostcb724]

I need some info on how to reduce the Nox emissions so I can pass this dreaded Texas inspection lol

I've seafoamed the car this morning but there was not a lot of smoke that came out. Does the amount of smoke vary or has anyone else had it where there was rarely any smoke?

I'm going to clean out my egr valve today and hope for some improvement there as well. Is there anything else I need to do besides drilling the ports which I can't do anytime soon?

Thanks

Jay

[ExplodingCake]

NOX is mostly EGR and EGR ports.

[Frostcb724]

Okay cool so im on the right track.

Any info on the low amount of smoke when seafoaming or is does that just means that I dont have much carbon build up in my engine and its pretty much clean in the runners?

[InvaderTrax]

Rubbing alcohol in the gas tank, and run the car hard right before you pull into the testing station so the cat's nice and hot (hot=efficient)

[wed3k]

higher octane and retard the timing.

[sdhardcoregamer]

Rubbing alcohol in the gas tank, and run the car hard right before you pull into the testing station so the cat's nice and hot (hot=efficient)

Well I dunno about rubbing alcohol but I used seafoam in the tank and used that tank before I went to test. As in put in in the gas tank a few days prior and run the tank down to get that seafoam through your system. As for the driving hard right before, you really only need to drive like 15-30 min. Not nessisarily hard, you just need to let the cat heat up so it'll burn the emissions better. I also usually change the plugs, air filter, and any other minor things that might help.

For the cat I usually hit the freeway for 10-15 min one way and then back then go test. The main thing is to get it tested within 10-15 min after you turn your car off after getting your cat hot. If you let it cool too long your NO will be higher and may not pass.

[Frostcb724]

Alright I cleaned out the Egr valve passage way and as stated earlier ran seafoam yet I still didnt pass (NOx). Here are my numbers:



Standard: 25mph 910 ,............. 15mph 1006


My readings: 25mph 1619 ,........... 15mph 1889


What else can i do to lower nitrogen oxide besides drilling out the ports because i dont have the tools for that at the moment.

[Lakersfan24]

I have the same problem out here in AZ but my was only 4 points. I've tried the timing, higher octane, sea foam, plugs, wires ect ect I think it just comes down to the o2 sensor and the EGR ports. I said screw it and I am changing the A1 manifold for an A6 and cleaning the ports and everything else before I do it. I cleaned out the EGR and the port were it is connected and that did not help. I would just do what I am about to do next week. I can think of anything else to do. I've been told it's the o2 or cat but I haven't tried that yet. Good luck

[wed3k]

egr valve is just the beginning of the passage way, you have to clean the ports.

[Sarthos]

o2 sensor should do the trick. If it's never been replaced, replacing it can help a TON. even help your mileage and HP too.

[wed3k]

no it wont.

[Fiveiron_42]

Well I had to pass emissions and all i did was run a tank of no ethanol premium gas in my accord until it was at a half of a tank and my score dropped 300 points...

[accordztech]

o2 sensor should do the trick. If it's never been replaced, replacing it can help a TON. even help your mileage and HP too.

not for nox.

If you retard the timming as wed2k said it will work up to a point, where it will just become more rich.

if you really want to hide nox, find a way to run richer it will hide it but only so much. Then you got to worry how rich you actually are running.

the alcahol thing would work.

But best bet is to clean the egr ports.

if you want ill sell you my oem one that I took apart and cleaned the egr ports. That way you can replace the whole intake manifold. but its a 90 91.

those numbers? there are 2 sets, what are they? max and measured?

if you are very close retarding the timing 2 degrees from stock will probably do it

[wed3k]

agreed, if the cut point is 800 you can richen it to the point where it may drop 200ppms. now you have to worry about everything else.

[Frostcb724]

I appreciate it guys I just decided to go ahead and take the whole IM off and do a thorough cleaning and get a new Cat because there aint no telling when the last time thats been changed lol