smog problems

[littledevil_87]

I just got my car smogged today and of course it had to fail. it is a 1990 mustang lx 5.0 and the only mods i have done are borla exhaust, k&n intake, JBA shroty headers, ford racing pulleys, and a JET mass air flow sensor. i basically failed the 25 mph test with having too much hydrocarbons (i had a 122 and needed a 96) not to metion i barely passed the 15 mph test (one more hydrocarbon and i would have failed that too. How can i pass smog? Are the parts i metioned earlier (even though they each stated that they were emissions legal for california) causing the problem? Should i remove some of them temporarily or is there anything else i can do that will allow me to pass smog?

[MagicRat]

The mass airflow sensor might be a problem, but I would look at some of the basics first.
Try a new oxygen sensor. They do not last forever, and are supposed to be changed about every 50k miles or so. When they start to go bad, they can produce too many hydrocarbons.

Also, try new plugs and wires; and make sure the ignition timing is set properly and the timing advance and the EGR valve work properly, then test it again.

Also, try changing the engine oil and filter before the test. For some reason, fresh oil helps the test a bit.
Finally, you still have a catilytic converter, right?
It might be bad, or contaminated, inside and is not too effective.

[littledevil_87]

thanks a lot for the tips. im gonna take a look at it first thing tomorrow morning and ill switch out the mass airflow sensor for the stock one too. hopefully that will do it. once again thanks.

[littledevil_87]

well, i failed again. i actually did worse than the first time. how do u know when u need new catalytic converters and oxygen sensors?

[bruce625]

Originally Posted by littledevil_87

well, i failed again. i actually did worse than the first time. how do u know when u need new catalytic converters and oxygen sensors?

I just went through the same deal with a 93 chev. Changed O2 sensor and it was worse. Also changed oil and plugs and wire but no better. This time the tech told me if this was his car he would have change the cat. Cost us about $80 bucks and a half day under the car. Passed with flying colors.
Good Luck