Looking for advice on de-ricing my 93 Civic VX

[ian]

Hi all,
I just bought a Civic VX that the previous owner thought he was making into a race car, but in reality all he did was make more work for me. My immediate goal for the car is to get it to pass smog in CA so I can get it registered and start driving it. I’m going to need to deal with 3 trouble codes (10, 12, & 48)

1st. problem: The car has no CAT. The previous owner installed a header and sold the stock manifold and CAT for scrap. I'd like to just install a CAT after the header and try for smog, but I don't think that that will fly in CA. I'd love to hear from anyone that has any knowledge on this issue. The 5 wire O2 sensor is installed in the header, but with the #48 code I don’t know if it’s still any good.

2nd problem : Trouble codes 10, 12, &48. The previous owner installed an aftermarket intake and some kind of wire breather valve on the rear left hand side of the intake manifold under the purge valve and there are vacuum lines unhooked. I found a troubleshooting guide for the #10 code and am in the process of going through that one now, but would still appreciate any advice on it. From what I’ve read about #12 I need to clean out the EGR ports and if that doesn’t work replace the EGR valve. Please let me know if anyone knows anything else about fixing this code, or if anyone knows of a how to on cleaning the EGR ports that is specific to the VX engine. As for the #48 code the previous owner relocated the O2 sensor so I need to find out if it’s a problem with his wiring job or a bad O2 sensor; all I know is to shake the sensor to see if it rattles. Any advice on testing/troubleshooting this code would be great.

Also, can anyone give a recommendation for a good VX shop manual, something with troubleshooting guides in it? I found a factory one for a 94 VX on ebay, but I don’t know what would be different between my 93 & the 94. If anyone knows of one for the computer I’d rather have that.

Please pitch in with whatever knowledge you have and thank you very much for your time. I'm still trying to figure out how to get pictures into posts, but I'll figure it out and get some up here ASAP.


Thanks,
Ian

[turbothrush]

your 93 is almost identical Gallery

[Christ]

If the header is Cali legal, you can get a cali legal aftermarket catalytic converter installed and be covered there.

The mesh breather is part of the PCV system. You need to check if your aftermarket intake has provisions for the PCV valve.

Your best bet to making it legal, if you don't care about performance upgrades, is to trade/sell that aftermarket intake for the stuff you need. (Stock intake, PCV system, and maybe some help installing it properly.)

I believe the PCV issue can also effect the EGR code, but I'm not sure about it.

[ian]

Sorry, the mesh breather thing is on the rear left of the intake manifold right under the purge valve, not on the valve cover. I don't know why I said valve cover, I'll edit that. I'll get pics up tonight too (someones coming to help me figure out how)

No, I don't care about the performance upgrades. Long term I'm looking for more MPG rather than HP. I'm still trying to find a definitive answer to whether or not the intake/header help or hurt MPG. everybody seems to have a different opinion. I saw a VX exhaust manifold on ebay for $70, other manifolds that look like they will fit sell for $40. Anybody know if the VX exhaust manifold is specific, or if others will work fine?

[WD40]

Intake and exhaust diameter are suppose to be the same .. you could restrict the intake to match.

[Ryland]

There is a strong pattern between after market exhausts on a VX and the 5 wire o2 sensor wearing out quickly, so I'm betting that your o2 sensor is bad.
The VX has the cat right up under the hood right on the exhaust manifold so it gets hot right away and stays hotter, I'm not sure if any other manifolds would fit or not.

[Brad9660]

If it was me, I would try to get the car back to stock, intake/exhaust. I have also wondered about aftermarket header/intake improving mpg's, but I know the civic can get great gas mileage completely stock, and it seems most people on here have stock exhaust and intake. My thinking is if you return the car to stock form, you can eliminate the troubles being anything to do with the modifications. Do you live near any salvage yards? If so you might be able to find the parts you need for pretty cheap, the junk yards here in St. Louis usually have a decent selection, and are much cheaper than ebay.

[ian]

Ok, I figured out how to get pictures in here.




Here is a picture of the engine compartment and one of the breather thing that's below the purge valve on the rear left of the intake manifold. I'm thinking that I should take off the breather thing and hook that loose vacuum tube up in place of it. It just looks to me that that is where it should go. What do you guys think? Does anyone know what this is supposed to look like?

[ian]

Originally Posted by Ryland

There is a strong pattern between after market exhausts on a VX and the 5 wire o2 sensor wearing out quickly, so I'm betting that your o2 sensor is bad.
The VX has the cat right up under the hood right on the exhaust manifold so it gets hot right away and stays hotter, I'm not sure if any other manifolds would fit or not.

That's what I was thinking. Is the CAT going to operate hot enough that far down stream to pass CA smog?

[ian]

Originally Posted by Ryland

There is a strong pattern between after market exhausts on a VX and the 5 wire o2 sensor wearing out quickly, so I'm betting that your o2 sensor is bad.
The VX has the cat right up under the hood right on the exhaust manifold so it gets hot right away and stays hotter, I'm not sure if any other manifolds would fit or not.

That's what I was thinking. Is the CAT going to operate hot enough that far down stream to pass CA smog?