How to get my non-CA VX to pass CA emissions test?

[Gary Palmer]

With the mileage you got on your drive back from Phoenix, I'd be very surprized it the O2 sensor was having any difficulties. You would not have been able to get the mileage you did, if it was not operating properly and if the engine wasn't going into lean burn.

If it were me, I'd do the plugs, wires and a new cat, then take it in to have it retested. Although a stock cat is not cheap, I would opt for it over an add on, further on down the exhaust, because of the fact that they have to get hot, in order to work properly and on the VX it has to work extra hard, because of the lean burn.

I would do some checking around, though, before I put a factory replacement in. I was able to get a new cat/lower exhaust replacement for my daughters 87 DX, for about $125, vs. $600-$700 for a factory unit. It replaced the custom factory unit with a stock cat, with some custom piping, to allow it to replace the stock unit. It worked fine and it was a whole lot less than getting a factory replacement.

I did have to replace it because of CA smog issues, as well.

[Rstb88]

I had a Ford Thunderbird that wouldn't pass emissions. So I had decided to put Seafoam in it. It worked wonderfully, i put it in through the brakebooster vacuum line and watched the smoke blow out. After the smoke cleared and redid the test I passed. Alot of people dont like this product but i refer it over some of the other stuff.

[RobbieVX]

thanks for all the advice. Gary, where did u get the stock replacement cat for so cheap? i think the O2 sensor is ok because the car has been running fine and still gets good milage when driven right, but i still might replace it to make sure. the previous owner said he replaced it mabey 3-5 years ago.

someone looked at my numbers and told me that my cat probably just wasnt hot enough because at 15mph it failed so badly and at 25 it wasnt so bad, anyone else think this could be the case? i drove the car maybe 4 miles from my work to the smog station, it sat for mabey 10-15 min with the engine off, and then the tech started it and drove it onto the rollers.

[GasSavers_Ryland]

if you have an impact wrench, it takes about half an hour to remove, and reinstall the cat, so you can inspect the inside of it to see if it looks ok, you might also check the heat shield around the cat to make sure it's still intact, as if it's missin it's not going to get/stay as warm, so it's not going to function as well.

[zpiloto]

Originally Posted by RobbieVX

someone looked at my numbers and told me that my cat probably just wasnt hot enough because at 15mph it failed so badly and at 25 it wasnt so bad, anyone else think this could be the case? i drove the car maybe 4 miles from my work to the smog station, it sat for mabey 10-15 min with the engine off, and then the tech started it and drove it onto the rollers.

It might be as simple as you did not drive the car enough to get the cat warmed up. You should drive it for about 20 minutes then go get it tested. A four mile drive and sitting for 15 minutes is probably going to hurt the reading a bit.

[RobbieVX]

^ yeah thats what i figured, but not sure if it would have hurt it enought to throw off the readings that much, just weird how at 15mph the readings are so high and 25 mph theyre low. ill try to remove and inspect the cat. as far as the heat shield, everything is still on there, the car is very clean and came from the orig owner.

does anyone know what model NGK plug the VX uses fromt he factory and what it should be gapped to?

[GasSavers_TomO]

The OEM spark plugs are NGK V-Power ZFR4F-11 and OEM gap is 1mm +/- .1mm

And be sure to check out the VX Lean Burn and General Tech post to get the most from the VX.

[Gary Palmer]

I don't recall the exact name of the place I got my cat from. I just did a little searching for pricing, on the internet. The place I got it from had the best price and from the pictures seemed to be similar to what other places were offering.

I don't have any idea if having the cat warmed up more would have made enough of a difference, to let you get it passed, or not. I usually try to take the car for a 30 mile ride on the freeway, before I take it in to get it tested. However, it don't know if it help's any, if the cat is bad, I have had to just get it replaced.

[garyhgaryh]

Robbie, what ever happened to your vx? Did you pass?

From what I understand, the reason why Honda came out with a CA VX is because the lean burn mode produces too much Nox which made it hard for the fed one to pass emissions in CA.

I failed about two months ago with my CA VX. I was running about 1500 PPM NOx.. I finally passed by getting a new intake (egr passageway clogged) and richening up my mixture by retarding my timing. Passed with NOx of about 120PPM.

If you want your car to pass smog, you have to richen up your mixture. Retard your timing for the test and bump it back up. I think you can a 2% leeway to retard it.

Gary

[RobbieVX]

hey gary,

i actually replaced the cat and it passed fine. i dont really understand why honda didnt sell the non-ca version in ca because it still puts out less NOX than the limit.

glad to see youre doing the ca vx to non-ca conversion. ill be watching it to see how it comes out. a year ago when i bought my car, i thought about doign the same thing, but then i found a nice originaly owner car in pheonix, so i picked it up.

where in CA are you? im in LA, but originally from Marin County.

ps nice list of cars, i have a 94 tt supra