BumperLT

Ok, backstory is we just bought the car 4 days ago. The guy it was purchased form lives in an area where cars dont have to pass emissions. The exhaust is what i believe to be a larg culprit in not passing emissions. It has a 4-1 header, and no catalytic converter, a nasty exhaust leak, and a badly made/welded exhaust system, into a skunk2 muffler. A new exhaust has already been purchased and is on the way, we're going to have a muffler shop put a cat between the header and cat-back, where is belongs. In the add, he advertised it had a 4-1 header and had converted the O2 sensor to a 4-wire. I don't know what that means exactly, or if it was even done properly, but I do know a bad O2 senser can cause a handful of problems, idle being one of them. It idles at about 1500, and when you tap the throttle a little bit (like youw ould for a carb'd car), it drops to about 600 or so and shakes ever so slightly at 600. 1500 is obviously too high, and i think 600 is a little too low, only because it shakes a little bit like its about to die. Will a new exhaust and cat fix this emissions problem, or do i need to look closer at the O2 sensor? Help puhlease.. thanks!

Also, when I'm going down a hill for a 30 seconds or so in gear but not on the throttle and just letting the engine keep the speed down, when i get on the throttle again after the hill it smokes, all 3 hondas I've had do this, is it normal? Is it possibly related to a failing O2 senser?

EMISSIONS REPORT (haha)


4-WIRE O2 SENSOR "CONVERSION"


FROM THERE IS GOES TO THIS PLUG, AND THEN DOWN TO THE O2 SENSOR AT THE END OF THE HEADER


GENERAL ENGINE SHOT

jvillagran2000

it's a given that if the cat converter is not present it will not pass emmisions

BumperLT

I agree, and that is in the process of being fixed, but the idle problem is intermitant... not steady, after i posted that up it idled great. If the idle problem is the cat, wouldnt it be a constant problem?

hatchattack92

A Catalytic converter has nothing to do with idle the cat. just reduces carbon monoxide and unburnt hydrocarbons and nitrogen oxide molecules. Hence why it wont pass emissions!! Also a bad O2 sensor will most likely cause u to fail as well. Do u have a check engine light?

BumperLT

Thats what i'm trying to say, I think i failed emission for sure cause of that cat, but also cause of something else... like an O2 sensor and that is why it idles bad sometimes. No there is no check engine light, the previous owner said he changed the o2 sensor to a 4-wire so the cel wouldnt be thrown? It may have a cel on but the light removed from the back of the cluster i suppose. I'll check it when i pull out the SRS lamp... unless someone knows how to get it to shut off. (EX steering wheel and cluster in a 92 CX hatch)