1995 Plymouth Neon wont pass emmissions test

I have a 1995 Neon with about 325000 KM engine rebuilt in 2000 (150000km)
and Timing belt broke in NOV making the pistons hitting the valves so I got
a used head.

It wont pass the Drive Clean test in Ontario

First Test ASM 2525 CURB IDLE
LIMIT READING LIMIT READING
HC PPM 75 163 FAIL 200 193 PASS
CO% .42 .35 PASS 1.00 .41
PASS
NO PPM 576 1401 FAIL

SECOND TEST
HC PPM 75 264 FAIL 200 272
FAIL
CO% .42 .46 FAIL 1.00 .27
PASS
NO PPM 576 1556 FAIL

its a 2.0L SOHC


Thanks Chris

 

from my experience you probably need a new catalytic converter.
also did you do an oil change before the test.
also consider a new pvc valve.

 

PS don't buy a cat from Chrysler just goto a generic store and pick up a
generic high flow I used one that had a flow rating for a 360 cubic inch
engine. cost like 120 cad.

also reset the computer by disconnecting the power on the car for a few
minutes. then drive nicely while seasoning the cat then 500 kms later take
it to a retest.

 

Don't forget to change the air filter.

 

I would definitely be checking to be sure you have NO vacuum leaks,
first. I would also change the oil, and make sure all tuneup related
stuff is OK - good plugs, wires, etc, and clean air filter. Then if
you can get hold of a laser thermometer, check temperature of cat
inlet and outlet. If the outlet isn't hotter than the inlet (at least
200 degrees, IIRC, replace the cat.

High hydrocarbons without raised CO, and high NOX is sometimes due to
running too lean - lean missfire lets raw hydrocarbons through, and
running lean also raises NOX because of high combustion temps.