I went to go get my FD smoged today, and guess what...it failed. I have the following mods on my car:

Large street ported motor
Intakes
HKS F Con ( can be tuned to stock - very rich)
DP, cat back
12 psi boost on 99 twins

I just replaced my 02 sensor, but the smog guy said he saw my cat had a dent and figured it was done for. He recommended a new cat. I was wondering if a new cat could solve the problem, and what would be the cheapest option (I don't plan to keep the cat very long) if it does. Do people have experience passing w this set up?

Thanks

 

Yup

 

It's technically against the law to have some of those parts on your car, since they are replacing OEM 'emissions components.' Many smog techs may not notice because they aren't familiar with FD's, or may not be too concerned as long as the car is not in blatant violation of the spirit of the laws.

You said your F-Con is tuned rich, that could be a problem. The stock ECU is programmed to use certain ignition timing and air/fuel ratios so the engine burns clean enough to pass an emissions test. If your HKS F-Con is tuned in a way that makes the engine run too rich or too lean during the emissions test, it will not pass even if you have a brand new OEM cat converter installed.

There are quite a few threads in the 3rd Gen section of the forums with advice on how to make an FD run cleaner. Search around there and you should find lots of useful info.

 

dented cat huh. I guess it depends on how dented it is.

I used to have an hks f-con. That thing was so pig rich that I began to worry about my motor's longevity due to carbon buildup. To say the least I only had it for six months before I went back to stock. Honestly, I don't know how you could even fathom passing smog with one lol...

IMO not only for smog purposes but engine longevity as well: you should tune down the boost to 10 psi and go back to stock. If you are absolutely in love with higher boost levels then get a pettit or something better. Yup be prepared to swap it back for stock whenever you smog it, but then again its only a 5 minute job.

 

Are you saying to swap the fcon w a stock ecu? Since its a piggy back can't I just unhook it?

 

What I mean is to just return it to stock. So yes just unhook it