F*** ing aircare (!) anyway re-installed the cat, oil/filter, new plugs and wires, hypertech program turned off, reading at SW marine were

HC, 1.4006 on a .500 limit, fail
CO , 2.26 on a 9.32 limit, pass
NOx, .9507 on a 1.24 limit

Went to Richmond, readings were

HC, 1.4817 on a .500 limit, fail
CO , 2.56 on a 9.32 limit, pass
NOx, .7626 on a 1.24 limit

Anyone has any ideas to get the HC's down??

Thx

 

change your *****

 

... like all pussies its an expensive one, especially with flanges welded onto it. Anything worthwhile adding to the gas?

Thx

 

Anything else to try beforeI replace this thing?

 

I don't think anything other than the cat will solve that.

 

Without a gas bench you are just guessing.

Some things to ponder,
High HC indicates un burnt Hydrocarbons. They don't necessarily have to come from your tail pipes during an IM240 test at Aircare.
The test is all the air at the back of the car, not just the tail pipes
If you smell fuel at the back of the car at any time this could be your issue.
Damaged fuel evaporation systems are a known issue with the "F" body.

If you smell any gas, start there. Of coarse it could be a dead cat or a misfire but it is a little presumptuous to diagnose the problem as positively the cat over the Internet.
Gerry

 

Thx Gerry, nice cutlass, remember it from an Olds show a few years ago. Anyway, no gas smell, ran CRC 'guaranteed to pass' additive throught it..

HC ; .7708 on a .500 limit, fail
CO ; .4051 on a 9.32 limt, pass
NOx; 1.28 on a 1.24 limit, fail

An GM Kleen combustion chamber cleaner through it

HC ; .5520 on a .500 limit, fail
CO ; .05345 on a 9.32 limt, pass
NOx; 1.29 on a 1.24 limit, fail

Any ideas on the NOx.... going the wrong way

 

AWWWWWWWWWWWW I did aircare today and I failed.

HC-->1.1823 (0.5000) FAIL
CO-->6.9089 (9.3200) PASS
NOx->2.0715 (1.2400) FAIL

Now I have to find out whats up with my car.

 

I passed aircare I had to replace my CAT and take out my performance chip.

HC-->0.0245 (0.5000) PASS
CO-->0.1039 (9.3200) PASS
NOx->0.7618 (1.2400) PASS

 

I'll see if a new EGR and checking out the fuel evaporation system helps