My 97 civic lx wont pass smog, I have dc 4-1 headers,greddy evo cat-back system and AEM pulleys and cold air intake,high flow cat(my old cat was connected to the manifold now it's under the car and I have a custom wiring for the 2nd O2 sensor).It passes the visual test but thats it really.Once it passed the 25 put not 15. Are there any tips to help it pass with out swaping all my old parts,(I heard that doesnt always work sometimes).I've gotten a few tune ups but it didnt really help and don't really want to spent tons at a smog gold repair station. Does any one from So cal might know of a place that will pass your car if you front then some extra money, I heard there around but dont know where to find them.

 

You could move to a different state. I know it's a pain, but I would probably put your old parts back on. I don't know any underground places.

 

This has worked but isn't gauranteed.

Don't drop your car off. Fill up with super and and an octane boost wouldn't hurt, I use BG44k which is like methamphetamines in octane form.

Keep the car running for at leat 1 hour. So if there's a line and your waiting, let it run at idle the whole time.

It worked for me in one of my old cars. I was double the output of Carbon Monoxide, and then I tried this method and passed, saving me 550$ which is what the cost of replacing whatever in order for me to pass.

Good Luck

 

You need to get your catalytic converter hot enough to light off. That's easy to do when the cat is built onto your manifold, but you've moved it much farther from the engine where the gasses are cooler, and replaced it with a lower restriction, cooler running catalytic converter. A hi-flow cat on a civic is really overkill. Using a standard OEM cat will probably allow you to pass the test, and should still bolt up with your aftermarket parts in place of the hi-flow part. Not all civics have the manifold-type cat, and you won't find a cat in a junkyard because it's not legal for them to sell them. Maybe you can find someone locally or on a message board that will part with theirs, or let you use it for a while. I don't have one, but I've gone through the same thing with my civic.