Emission test failed! HELP~
 

Hi guys!
I have 93 fd which has a stock turbo and intercooler. It has got Blitz air filter and HKS Hi-power muffler. So, this car is pretty much stock.

Today, I went to take emission test, and it failed. Everything has passed except CO reading. the limit CO reading is 20.0000 in Colorado. My car reads 25.0000. The guy from the emission center gave me a paper, and it shows that air/fuel ratio is rich. My car has stock fuel injectors and fuel rail.

Maybe, I have dirty injectors? dirty air filters?
is it because of turbo problem? My stock turbo is not working properly, I do not feel secondary turbo working; however, the boost spikes untill 14psi. I do not feel that much boost, and I hear some strange noise from the turbo area. It is a weird symptom.

How can I fix the problem to pass emission test?
Thank you guys!

I'd guess the air pump is not working, or the pre and/or main cat is in bad shape. If the precat or main cat is clogged or collapsing, you would have boost troubles.

There are lots of threads on emissions - you will learn a lot if you search.

You have a boost spike on stock fuel/injectors to 14psi?! Yet you're worried about emissions?

Try fixing that 14psi spike, and save your motor, before you worry about it getting passed so you can drive the thing.

sounds like he could be right (not putting too much thought into it). you should get that 'lil spike under control though or your car won't be able to take an emissions test anymore. get a downpipe on it and check your main catalytic for starters.

Check all your intercooler plumbing lines from the y-pipe all the way to the elbow. It sounds like you have a torn intercooler line. If there is a tear in the hose and the engine is not getting all the air that the turbo's are feeding it then maybe it's running rich because the lack of air.

If CO is the only number too high it often means that the engine was not warmed-up enough. Try driving around for a couple hours before taking your next emissions test.

Exactly.. That's pretty close to passing. I'd do all of the standard pre-emissions stuff and have it restested.

Change oil.
Fresh plugs.
Clean air filter.
Run it hard before testing to get the cat nice & hot.
The single most important thing: Sit in the passenger's seat while the tester does the test (You can, just ask), show him the boost gauge and ask him to try to keep it in vacuum. Favor lugging it over boosting it.