Hello,

I recently purchased a 1997 FD3S here in Okinawa. The vehicle came with a JCI but because it was J plated, I have to pass another inspection to get the SOFA plate. Well, long story short, the vehicle failed the inspection miserably. I was able to correct most of the issues but I'm having difficulty with emission. It's at around 7.0 CO and 700-1000 HC. It's already running on 93 octane and the current tank has a fuel mix in it. This was measured when the vehicle was already at operating temperature. My friend is saying maybe the car has an aftermarket cat converter. Does anyone else here have any suggestion for me? Because if it's not the cat, I don't know where to go from here.

thank you

 

What do you mean by “fuel mix”? I don’t have to deal with emissions but since no one else chimed in...if you mean premixed 2-cycle oil in the fuel I gotta think that’s not helping, at all.

 

yea boss. I'm currently trying to look at ECU and CAT. See if they're stock. I hope they are not. Because then it would be an easy fix. hopefully ;

 

I would first look to see how many converters are in the exhaust system. Is it a factory exhaust?

 

^ Since it’s JDM, shouldn’t there be just the main catalytic converter? IIRC they never were able to experience the joy of our NADM precats.

And OP, we still don’t know if you’re premixing.

 

I just confirmed that the vehicle has stock ECU and cat. We also found the vehicle had a racing spark plugs. We replaced the plugs with OEM ones today.

 

It still has stock cat. We found out today that the engine had racing spark plugs. We replaced them today. The fuel mix was the racing premix. I was told that it will burn cleaner and help the engine last longer. I plan to not use it for the fuel tank when I try to pass emission next time.

 

I don’t think plugs will make much difference. But using fuel WITHOUT oil added should.

 

^ I agree. I'm just trying to do everything that might help at this point. The only option I have left is burning the current tank with the premix then top it off without the premix. 1st gear only all the way to the testing site IOT make the cat melting hot (I was told this helps).

 

Burning up all the fuel is best, but if you must, the tank has a drain.
If you can use a little ethanol blend fuel JUST for the test (and there after low or non-ethanol) that might help too.
Hopefully the stock cat’s efficiency wasn’t reduced by the premix.