Hi there, new to the forum. Bought a 93 DX hatch recently, took it to smog and failed. Pretty badly. Emission results below:


Now some details: 283,000 miles, looks like the original cat. Previous owner replaced the engine with a JDM D15B. I replaced spark plugs, wires, did anoil change. Previous exhaust had a huge hole in it so I replace it with a brand new one. Plugs seem fine after taking a look at them. Car seems to run fine although when hot, starts to idle really low (below 500rpm). CA inspection place said it passed everything else (timing, fuel cap, visual).

From reading other posts, it looks like one variable could be the ECU, since it looks like the car was previously M/T swapped. Aside from that, and a new catalytic converter and possibly o2 sensor (which looks new) unsure of what direction to go in on this as the measurements are so high. My first guess is that since the catalytic converter looks original, 283,000 miles has rendered it toast, and its running almost like it has no cat. I've looked inside and while there doesn't appear to be anything clogged, I"m unsure of its functioning efficiency.

Figured I'd come on here to get other people's take on this. Thanks in advance!

 

I would say getting a new catalytic converter probably would drop the emissions quite a bit easily to a passing result. Old '89 civic I had went from failing miserably 1 week, the next with a new cat it passed with nearly 0's. Got a WOW! from the tech, kept the result paper too. I got lucky..

 

New air filter (or atleast blow it out with compressed air) a can of seafoam thru the gas tank. Take off the cat and pour some seafoam in it and let it soak for a bit. Put it back together and then RUN THE HECK out of the engine, Look up "Italian tune up" sometimes the engine just needs the crud literally blown out of it. If that doesnt do it, then maybe a universal cat