I got a 1991 Honda Civic with a 1.6L SOHC Non-V-TEC ZC Engine in it (swap from a 1.5). I took it in for emissions and the score came back around the 5-6000 area if I can remember correctly. The mechanic said it should be an 800 or lower. Anyways he said he would fix it and be "fair" with me... So I came back a few days later and he didnt even touch it[:@], but my buddy said he was a good guy so I gave him a couple more days, still nothing! Then I kept asking him for a price quote and he said 500-1000 (f that) So anyways im going to take it back and do it myself, the only reason I let him work on it was because I didnt know the problem. So if anyone knows what would cause horrible emissions please let me know! Also the engine only has about 150k on it. And if anyone knows what kind of parts could of been tampered with to give more HP, but would cause bad emissions please let me know as well, cause im positive the guy who had it before did some cheep modifications for more power.

Thanks guys

 

What emission did you fail? HC,CO,NOx, or all three? I would first check the air filter and spark plugs. If you haven't changed the air filter, spark plugs, plug wires, and fuel filter in a while that might be a good place to start. Do you have a cat and does it work properly? The cat burns off alot of emissions so if its not working then that would cause you to fail. Also, your car probably doesn't have a secondary oxygen sensor to determine if the cat is working.

 

Pretty common for some idiot to have hollowed out the catalytic converter in a quest for more power. Take one of the pipes off at the flange and look inside.

 

Yeah I was thinking about the cat I will check that out, I did a tune up on the car before I brought it in, and even put new plug wires on. I dont even have the paper to tell me what I failed so I dont know much there. I also have a cold air intake on the car.

 

Oh yeah also I was thinking, since its an engine swap to a different engine, wouldn it be possible that some sensors are different of the PCV valve is different causing bad emissions?

 

I just bought my civic as well, and failed the first emessions test. They carbon cleaned the motor(something like that) and the score ended up being 1/4 of what it was and it passed brilliantly. Cost $200.

 

You can try running Seafoam through the engine which is an engine cleaner. There is a write up about it in the DIY section.