Just came back from the test only station and I failed the emissions test by a landslide....here are the numbers:

15MPH HC MAX=89 MEASURED=98
25MPH HC MAX=54 MEASURED=79

15MPH NO MAX=708 MEASURED=804
25MPH NO MAX=746 MEASURED=411

Timing is 18 degrees BTDC
CAT is only a year old
NEW Plugs gapped to spec
91 octane w/ NOS octane booster
Fuel pressure set to 44 psi

I am going to put on a new cat, retard the timing to 15 degrees, check the plugs, and get a new cap and rotor(starting to go out) .....Anyone have any other suggestions to get this thing to pass? Any feedback is much appreciated....Thanks

 

Dont use octane booster.

 

I'd go with the new cat and cap & rotor. fuel filter clean? or replaced? new pcv? I don't about the nos octane booster but just run regular 91.

 

Your numbers are not that bad. If you gross polluted, that would be another story. You retard your timing to 12 degrees BTDC and your NOX should pass easily. HC's are the product of misfires. Adjust the valves and do an ignition tune up-spark plugs at least -NGK's or ND's. Since you did not post your CO, I am guessing that it was passing, you might be able to bump your fuel pressure a couple of pounds. If you run too lean, that will up your NOX and your HC's. You replaced your Cat? I have seen more than one car fail because of a poor quality aftermarket Cat. You get what you pay for.

 

was your cat good and hot? drive around for a half hour before taking it in again.

 

The cat is only a year old, and I drove around for a good hour and a half before the test and left the car running up until 10 min before testing. I just replaced the plugs with NGK 7's 700 miles ago but I need to verify the gaps again. What fuel pressure should I be running at? Also the fuel filter is new and the cat that is on the car is the 9400 series carsound cat.

And for the CO numbers.... MAX=.53@15MPH and .51@25MPH ....I scored .12 and .11 so that did pass.

Thanks for the help guys and since I have a hook up on getting carsound cats...I am going to replace the one that is on there just to clean up as much as possible.

Let me know what fuel pressure I should be at with timing set at 12 degrees BTDC. Thanks,

 

make sure your car is warm next time

 

Oil change, 20w50 to help with the HC's