My 93 Honda Civic VX failed California smog test!

[crz650]

Alternative title: Introducing my 1993 Honda Civic VX Hatchback grocery delivery workhorse and touge racer!

Hello everyone. I've had an account on ecomodder.com since 2011 but I don't post much. A few years ago I wanted to make a thread for my VX I bought in 2015 and now that I failed smog and having bad mpgs I finally have a reason to make one!

First let's start with the smog. I failed by just 0.1 points in the CO category. The max is 0.42 and I had a 0.43. I've already installed new spark plugs, air filter, oil change and distributor(the old one was causing a lot of hesitation problems). What else should I do before going back for the retest? Since I only failed by one point I don't think I have to do anything major and what I've done so far will do the trick, but my emissions are really high and would like to bring them down to normal VX levels.

Smog related to do list:
Clean Egr valve
Swap 4 wire 02 sensor for the spare 5 wire I have from my old VX
New catalytic converter? Hard to find
Replace cracked exhaust manifold
...

Part 2 of thread: Introducing my VX (~150-160k miles, odometer only works intermittently)
I bought this in June 2015 after I crashed my red VX in March of 2015 from a man who was the 2nd or 3rd owner in San Francisco with the odometer at 115k. It's was stolen from him 6 or 7 times but it sill ran like a champ. I've been using it to do deliveries for Google Shopping Express and now Instacart. I've driven it from San Francisco to New Mexico, LA and Reno several times and never had any big issues. Sometimes I'll drive to the Santa Cruz mountains and try to keep up with my friends who race their BRZs and E30 BMWs but mostly it's just normal Bay Area driving.

Things I've done so far
New tires about 5k miles ago General Altimax Rt43 (couldn't find Michelin Defenders in my size)
Wool seat covers, Sheepskin steering wheel cover, handbrake and shift knob cover
Short shifter with weighted steel shift knob
Removed moldy carpet
Rain guards
Maintenance: water pump, timing belt, fuel filter, valve cover gasket august 2018
Recently did spark plugs and air filter
Painted old wiper arms
LED headlights
LED turn signals
New battery
New spark plug wires
New aftermarket distributor
New thermostat and Radiator cap

To do list:
Install new Radiator and hoses I have laying around
New brake pads
Pass smog
New suspension, lower a couple inches
Front air dam
Paint rims black
Clean and wax
Amp for sound system
Fix ignition keyhole. (damages when car was stolen)
Install security system
LED brake bulbs
Floor mats
Louder horn
New resonator and muffler (the one I currently have sucks and it's REALLY loud inside)
Replace bad trailing arm bushing
Find oil and coolant leaks
Fix engine check lights, codes 1,12,22

[Ecky]

I would say that cracked exhaust manifold and especially the wrong O2 sensor would be contributing to your emissions issues.

Love seeing VXs still on the road. I snapped a picture of one a few days ago - the rear wheel wells looked like swiss cheese.

[Piotrsko]

Well a quick check says code 1 is your O2 zensor, 12 is faulty egr , 22 is some odd valve named VTEC failure. Cleaning the EGR Will lower idle CO, the O2 might lower it across the rpm range. Having spent a couple of eternities in the LA AQMD, how are you getting smog with a CEL set? Worse case back the distributor off a degree or 2. Keep it within specs but on low side of tolerances advanced

[crz650]

Originally Posted by Piotrsko

Well a quick check says code 1 is your O2 zensor, 12 is faulty egr , 22 is some odd valve named VTEC failure. Cleaning the EGR Will lower idle CO, the O2 might lower it across the rpm range. Having spent a couple of eternities in the LA AQMD, how are you getting smog with a CEL set? Worse case back the distributor off a degree or 2. Keep it within specs but on low side of tolerances advanced

Well the CEL isn't on all the time. Sometimes it comes on during long highway drives but not all the time.

[whaemmel]

Hi, Is your rig a 49 state or CA VX?. The CA VX uses different ecu and O2 sensor. The smog tech may not notice # of o2 sensor wires on visual portion. If you are in enhanced smog test area (dyno test) as mentioned retarding distributor on low end of spec can work(I move it back after smogging and mark original position. I wonder if vtec seal needs replacing or diaphragm in vtec solenoid is going. I like to run a bottle of lucas injection cleaner to make sure the injectors are atomizing well. I'm not a smog tech but have dealt with a few smog repairs since getting ASE cert. in 1991. I always try simple fixes first. A can of carb/intake cleaner is good vacuum leak tester, cleaning
the throttle body can help as well.

[crz650]

Originally Posted by whaemmel

Hi, Is your rig a 49 state or CA VX?. The CA VX uses different ecu and O2 sensor. The smog tech may not notice # of o2 sensor wires on visual portion. If you are in enhanced smog test area (dyno test) as mentioned retarding distributor on low end of spec can work(I move it back after smogging and mark original position. I wonder if vtec seal needs replacing or diaphragm in vtec solenoid is going. I like to run a bottle of lucas injection cleaner to make sure the injectors are atomizing well. I'm not a smog tech but have dealt with a few smog repairs since getting ASE cert. in 1991. I always try simple fixes first. A can of carb/intake cleaner is good vacuum leak tester, cleaning
the throttle body can help as well.

Thanks, I'll be cleaning my intake and doing an oil change before I take it for a retest today. Wish me luck!

[whaemmel]

Good Luck, Ca smog particularly enhanced can be a pain, especially on older cars, Best Will

[California98Civic]

Really glad to see an old Civic return to service. You got lots of good advice in this thread. I hope you passed. Let us know. If not, you can try cleaning the catalyst.

[crz650]

Just came back from the smog place and it failed again! Fortunately the guy who runs the shop is super cool and isn't charging me for the 4th failed retest. He put some seafoam in one of the vacuum lines and there was a ton of smoke coming out of the exhaust manifold so that definitely needs to be replaced ASAP because I only have a 5 days left on my temporary registration. I'll be ordering the parts today.

The tricky part is finding the right exhaust manifold as the OEM manifolds are discontinued and the VX model has a unique manifold style. If anyone could link me to a good VX exhaust manifold I would greatly appreciate it! Shopping for non OEM parts gives me headaches lol

[Ecky]

I've never seen a vehicle *not* produce tremendous amount of if black smoke when seafoam is fed into one of the lines, FWIW.