1998 Civic EX 4 door
d16y8

k&n CAI with CARB EO sticker.
4-2-1 dc header HHC5513 with CARB EO sticker.
dc header carb eo number: D-370-6
carb eo date: April 23, 2001

i still have the cat. and my header is one of those kinds where you need to extend the O2 sensor and route it closer to the cat. DC provided the wire extension.

my car runs fine. never had a check engine light or error message. no weird smoke coming from the exhaust. i'm still running with the original catalytic converter, stock exhaust pipes and muffler. engine doesn't struggle or lag.

2 years ago, i only had the CAI and passed. it was quick, there were no questions asked from the smog guy. i passed, signed the papers, and done.

1 year ago, i installed the DC header b/c i had a cracked exhaust manifold.

now, my registration is due in a couple of months and i need to smog it.

assuming my car has no mechanical problems, and given my 2 mods, is there any reason why i would fail the test either visually or sniff?

here's the Executive Order for the DC header: read it here: http://arb.ca.gov/msprog/aftermkt/de...eo/D-370-6.pdf

thanks for your help.

 

It should pass with CAT and CARB legal header, if in doubt tell them to do a test run first.

btw, you are among the dated member with the least post.

 

You should pass, if someone gives you a hard time just go somewhere else.

 

So, I failed smog. Visual Inspection ok. But emissions failed. The tech told me to first fill up with premium gas. after I've gone through all of the low octane and high octane flows through, come back and retest.

I asked, what if I use high octane, and still don't pass? the tech said: "it's your cat. it's probably old, but hopefully that's not the case. Also come back when it's cold. come back in the morning. your chances of failing are higher when it's hot and muggy."

I also asked: this has nothing to do with my header or intake does it? The tech answered, "no. Everything is hooked up just fine. Some techs will be a b**ch about it and fail you regardless of carb and paperwork, but you're fine."

I attached my smog slips. Do you agree with the tech? Is my car so old that I just need to start filling up with premium?

 

correction my car has 187,367 miles

 

Seeing high HC (BARELY passed) and NOx at the same time does suggest that the cat is bad. CO is also elevated. This all suggests that the pollutants leaving the engine are within design limits, but the cat is not doing its job to clean up what is left.

Is the spark timing right? Is there any misfiring at all? Do you have a heat shield on the cat (and ideally on the front pipes like stock, but I don't think anyone does that with headers). The cat works better if it can heat up.

On the California models with EGR, once in a while you must take the EGR valve and intake manifold plate off and clean out the passages. Inoperable EGR makes NOx go up. The ECU's self-test may not detect a partial blockage.

Also you should censor those pictures to black out your license # and VIN.