Failing emissions badly. please help

[tonicinwhite]

have an 88 944 turbo with approx. 92,000 miles.

its failing emissions not for a bad cat (Nox) but for CO and the HC's

limit for Virginia is 110 for HC's.... i got 205

limit for CO% is .44 i got 3.19

I changed the oil, air filter and put some new bosch platinum plugs in it last weekend shortly after it failed the first time with similar numbers. does any one have ANY ideas as to what could cause these numbers to be so far off the charts

the car is chipped with stage 2 chips and a lindsey boost enhancer but it passed in 2002 with the same setup with flying colors

Thank you in advance all ideas are surely welcome

Jeff

[dsumners]

likely O2 sensor.

have an 88 944 turbo with approx. 92,000 miles.

its failing emissions not for a bad cat (Nox) but for CO and the HC's

limit for Virginia is 110 for HC's.... i got 205

limit for CO% is .44 i got 3.19

I changed the oil, air filter and put some new bosch platinum plugs in it last weekend shortly after it failed the first time with similar numbers. does any one have ANY ideas as to what could cause these numbers to be so far off the charts

the car is chipped with stage 2 chips and a lindsey boost enhancer but it passed in 2002 with the same setup with flying colors

Thank you in advance all ideas are surely welcome

Jeff

[0586slb]

its failing emissions not for a bad cat (Nox) but for CO and the HC's

limit for Virginia is 110 for HC's.... i got 205

limit for CO% is .44 i got 3.19

How have you ruled out the Cat being bad? The Cats are TWCs, so NOx is converted to N2 and the Oxygen liberated is used to combine with CO to produce CO2 and with the Hydrocarbons to produce CO2 and H2O. So the Cat is clearly not doing its job. Treat correctly, the Cat should last the life of the vehicle.

The major damaging factors to the Cat are; mechanical shock, oil smoke (cloggs the core) and unburnt fuel (causes excessive temperatures in the Cat and a 'core meltdown'). Your modification setup may be causing excessive unburnt fuel. You say it passed with this set-up in 2002, however it sounds like the Cat was coping with it then, however 4 years later it may be overwhelmed.

I've just read your other post, you say you have smoking exhaust problems... Can you ascertain if it is oil smoke (bluish, hangs around a bit) or rich poorly burnt fuel (black, petrol smell)?

Edited July 30, 2006 by 0586slb

[podemski]

its failing emissions not for a bad cat (Nox) but for CO and the HC's

limit for Virginia is 110 for HC's.... i got 205

limit for CO% is .44 i got 3.19

How have you ruled out the Cat being bad? The Cats are TWCs, so NOx is converted to N2 and the Oxygen liberated is used to combine with CO to produce CO2 and with the Hydrocarbons to produce CO2 and H2O. So the Cat is clearly not doing its job. Treat correctly, the Cat should last the life of the vehicle.

The major damaging factors to the Cat are; mechanical shock, oil smoke (cloggs the core) and unburnt fuel (causes excessive temperatures in the Cat and a 'core meltdown'). Your modification setup may be causing excessive unburnt fuel. You say it passed with this set-up in 2002, however it sounds like the Cat was coping with it then, however 4 years later it may be overwhelmed.

I've just read your other post, you say you have smoking exhaust problems... Can you ascertain if it is oil smoke (bluish, hangs around a bit) or rich poorly burnt fuel (black, petrol smell)?

How long has it been since you changed to 0ygen sensor? I had similar emission problems and that was the root cause.