Failed emissions

[JeffW]

I just got back from taking the GN through it's dreaded annual inspection. Failed with 553ppm on hydrocarbons, 220ppm limit. CO was 1.5% with 1.2% limit. Outside temp was about 30 degrees. I could only get the car to about 160 - 164 temp. I seem to be having some troubles with running rich at idle. When I first got in line, the BLMs were @ 105. I had to sit in line for about an hour. Over that hour the integrater values were bouncing around 130 to 135, and the BLM worked it's way up to 121 by the time I tested. TPS was .42, IAC was 17 to 19, filtered load variable was in the mid 30s. I thought I had a good chance of passing at that point. I'm running 868 36lb injectors and a mild 93 octane chip burned for the 868s by Joe Lubrant. I've passed the past 2 years with the same chip. The only major change to the car since the last inspection was the OEM MAF went south and I replaced it with an LS1 MAF/Translator. The translator is set to read a "normal" chip. I do run a "high flow (yeah right)" 3"cat with internals intact on a THDP. I'm wondering if either the EGR has ceased to function or my cat has given up. It has seen leaded race fuel 5 or 10 times at the track. I had also just replaced spark plugs (they read rich) CRT43s @0.035", and a new GM O2 sensor.
I guess I'll be checking EGR functionality next, maybe replace the cat and give Turbodave a shout for a "special" chip. Any other ideas ?

[gofstbuick]

Do you have access to a digital pyromter? If so, do a temp test on the cat. First warm the car up (so it goes into closed loop), then do a 3+ minute freeway run above 65mph. When you bring the vehicle to a stop, immediately get out and check the inlet / outlet (front and back of cat) temps on the cat. The outlet should be at least 100* hotter than the inlet (ex.: inlet temp is 290* and outlet is 400*). It takes energy to complete the catalyst process, so that is why the back of the cat will be hotter than the fron of the cat. But, you cannot just idle the engine to chcek the temp readings, because the (heat generated by the) turbo will sometimes create a false fail.

[gofstbuick]

Also, what is the O2 content and CO2 content results on your smog test?

[Black Car]

What temp is the radiator fan set to come on? Most chips call for the fan by 170*.
You could get another chip programmed to NOT turn the fan on till 195*.
Another way is to partly block the radiator with cardboard so it will heat up.
You need the engine to be hotter than 180* IMHO.

Not saying that there could be other things that needs looking at too.

Gary

[jastrckl]

leaded fuel through a cat==dead cat. period.

[JeffW]

No access to a pyrometer unless I can find one at an exhaust shop. Our emissions here only checks HC and CO. No O2 or CO2 numbers available. I think my fans are kicking on by 170*. Due to odd circumstances, the last 2 years I was testing in April and was able to get the temps up over 190. I'm sure that had alot to do with it, but I also agree the cat is probably gone due to the race fuel. At this point I've some different registration arrangements that will not require inspection..nuff said