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-   -   VX Failed smog... High NOx, advice? (https://www.fuelly.com/forums/f10/vx-failed-smog-high-nox-advice-8499.html)

jshelton441 05-19-2008 08:08 PM

VX Failed smog... High NOx, advice?
 
Really high NOx on a 277+ mile VX.

O2 "looks" new, as in wiring looks clean compared to every other connector in sight.

EGR I "think" is by the VTEC solenoid, also looks cleaner than other parts.

I'm doing a search on the EGR cleaning right now, but any advice otherwise is greatly appreciated.

Thanks a lot guys,

Jason

roadsterbum 05-19-2008 09:01 PM

For high NOx, cleaning the EGR will definitely help, but so will getting a new catalytic converter. I replaced the cat on my Miata that failed smog due to high NOx, and it passed with flying colors.

jshelton441 05-20-2008 04:51 AM

Sounds good I will do both, just ordered a MagnaFlow cat for $115 from Summit and I will clean the EGR today.

Lug_Nut 05-20-2008 05:56 AM

Reduce the advance on the spark timing for a quick and temporary reduction in the conditions that can create NOx from N2 and any unconsumed O2. Higher cylinder pressure (and temperature) increases formation of NOx. Lower compression (difficult to do temporarily) and later ignition drop the peak cylinder pressure and make it more difficult for excess oxygen to combine with the otherwise relatively inert nitrogen.
The retardation will cause power to drop a bit as thermal efficiency drops, but the timing can be re-advanced when you get home after the test.

101mpg 05-20-2008 10:06 AM

Three words. "Guaranteed to pass."

You go to your auto parts store, dump a bottle into half a tank, better yet running on fumes, then add gas to halfway to mix it well, drive 100 miles and then go get re-smogged. Works every time.

If it doesn't, but you are CLOSE - run tank to empty, put in two bottles of Gumout fuel system cleaner - the $10ish bottles at your auto parts store, fill tank to half, go 1-200 miles, get the fuel system CLEAN - then put Guaranteed to Pass in your tank. Will pass smog.

Then go get vehicle fixed appropriately as this will give you better FE.

jshelton441 05-26-2008 12:32 PM

The "direct fit" cat from Magnaflow directly fit nothing on my car, seems that the cat bolts directly to the manifold and angles to a downpipe. The piece I got is a straight section.

LUCKILY in taking all this apart I found that the manifold was split nicely across the top from the oxygen sensor bung straight back towards the engine, which might explain the pungent smell every time I got out of the car. The rattling broken heat shield was taken off under the body yesterday too...

So, if you guys don't mind, a few more questions...

1) I now need a new manifold or header, is there a good place to get one online or otherwise that is CALIFORNIA LEGAL?

2) Does anyone have an aftermarket or retail source for the ORIGINAL STYLE offset cat?

Thanks guys, I'd just like to get this thing DRIVABLE and registered so I can actually use it...

getnpsi 05-26-2008 01:40 PM

i saw a wrecked sohc civic with a dc sports header on it at the junkyard. it had a CARB plaque on it.

GasSavers_Dust 05-28-2008 05:38 AM

You may be paying more for a replacement than you will for a header. I think most brand names have CARB stickers.

Danronian 05-28-2008 10:52 AM

I've seen OEM replacement manifolds and Cats sell on ebay for under $200 but I'm not sure how often they are on there. If you would buy a header for the car that is carb legal you would have to replace the cat with one not meant for the car so I doubt it would pass CA emissions in that case. You should be able to find an aftermarket OEM replacement manifold/cat somewhere hopefully... good luck!

jshelton441 05-28-2008 02:03 PM

So far I am going with a Hedman 4-2-1 header and a Magnaflow cat, both have CARB numbers on them for pre OBDII cars. Guess we'll see when I'm at the shop!


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