)2overt SS

Well... went for an emissions test today... and I failed!!! And now I'm frantically trying to figured out why!?

Just for comparison. 40km/h test

Emissions test 2 years ago: HC ppm - 5, CO% - 0.11 and NO ppm - 313

Emissions test just now: HC ppm - 57, CO% 0.52 and NO ppm - 401

I passed the idling test no problem. (but still a significant increase since 2 years ago)

Whats the deal? Ignore my mufflex y-pipe... I have a custom y-pipe with two cats that I swapped on for the e-test.

Questions:

1) How far back is TOO far for the cats to not get hot enough? Anyone with LT who passed have pictures?

2) I unhooked my battery to clear the "defective cats" code I was getting from when I had my mufflex y-pipe on. Now... I know that clears the computers "driving memory" correct? When they did the test the car had been off for 20-25 min and cooled down. So when they did the test... could the car have been on open loop (not reading the O2 sensors) and since the memory was cleared, the computer could have been dumping in fuel untill it warmed up to closed loop?

All I did was add LT and move the cats back! Oh... and some welding was done on the exhaust right before the e-test... any effect from that?

Sorry for the long post... but I'm just in a little shock... I was expecting to pass no problems.

Thanks

EDIT The reason I got the "computer memory" and "open loop as a theory is because.. in the shop, I could smell raw fuel (as with the technician) but after a drive and having a sniff of my exhaust again.. it was clean.. no smell of fuel.

jchevy

I just passed with flying colors. Maybe one of your cats is bad? Do you have all the emissions hook ups on your headers?

thirteen20z28

did you drive it for a couple days after disconnecting the battery but before the sniffer test? the computer has to relearn and adjust the fuel trims. were the sniffer values the reason you failed, or were there codes or something else? on an obd2 car, i would think the secondary o2 sensors would throw a code if the cats weren't working (or do you have simulators?)

)2overt SS

Thanks a lot for your input guys.

For the test I didn't have the AIR tubes hooked up. I unhooked them a while ago because they cluttered the engine bay, and I knew the AIR is just to heat up the cats quicker.

So after failing... I researched about what would cause high HC and CO... I found it's either because I'm running rich... or my cats weren't functioning (not getting hot enough)

So for kicks I hooked back up the AIR tubes, went to a DIFFERENT testing facility and voila! Passed with better results than 2 years ago! HC - 14, CO% - 0.00!!! and NO - 301

I've come up with a few explinations for this.

1) I drove a fair distance before the 2nd test and got the cats really hot, and then went straight to have the test done... no cooling down. So the cats were fully functional this time. When they other guys did the test... the car cooled down in the lot, and then they didn't warm it up. I have a friend who's a mechanic and told me the cars has to be running for 15 min at least to get warm and in closed loop. The other guys didn't run it for more than 2 min before testing.

2) The first test I did, the equipment used was faulty (just a theory).

I still refuse to believe that the AIR would reduces emissions like that... so I think it all came down to my cats being too cold.

Thanks again guys for taking the time to read my original post. I know it was kinda long, but I'm very appreciative.

I hope this helps other people out who might be having trouble passing emissions.