Hey guys, just tried to do a smog check and failed the ASM Emission Test on my E46 M3.

I passed on the 15 mph test but barely, Max 49 and i measured a 49, on the 25 mph test is where I failed, Max was 33 and i measured a 38. Any ideas what that would be?

car currently have 65,000 miles on it, drove the car for about 10 mins to the smog shop and idled for another 10 before testing, inspection 2 was done ~30k miles ago and inspect 1 was done 3000 miles ago along with 6 new coil ignitors since my oem ones went bad.



-Simon

 

Do you have the stock cats/exhaust on it?

Honestly I would have just drove the car longer than 10min before going in. Your oil temp probably hadn't even got up into normal range in that amount of time. I'm guessing it also cooled down too much when it was idling for 10min.

I usually drive my car pretty hard for 20-30 min then roll into the smog shop.

 

yeah id go drive it hard for a while... and then go into the smog shop...my dads z4m takes up to and sometimes more than 15minutes for the temps to get "pefect"...the redline limit increases slowly until the car is fully warmed up then its good to go...

 

HC's are purely unburnt fuel so +1 go get the car hot and get it re-tested.

Did you replace the plugs when you did the coils?

 

i'll try again over the weekend, going to drive it and warm it up more before testing. I'm on stock headers and cats and nothing has changed since i last smogged it and it passed with flying colors last 2 times. I didn't change the plugs when I changed the coilpacks because there were only 20k miles on them and ~30k now.

 

I ran the car at 4k rpms for a good minute then normal drive then do it again a couple more times, fluke suggested it and it worked magic on both cars i smogged this year.

 

Well OEM cats have a shelf life of only 7 years, my guess is that they are done, but like others say warning things up is supposedly the fix but won't work everytime.

 

Will E-85 have the same effect on this as our cars? If so try running 3 gallons of E-85 which has the tendancy to burn more thuroughly.

 

Try seafoam

 

Here's what I've done before going in for smog.

Once I let the car get up to the normal operating temperature, I'll get on the freeway so you can get the car up to a good cruising speed. I'll drop it down to where I am staying at the same speed, but I'll increase the RPM's up to around 5K-6K and drive like that for about 1 - 2 minutes. Then I'll drop the RPM's back down by shifting back in to a higher gear. Do that about 2 - 3 times and I can notice that the cat is hot as you can feel the heat starting to warm the floor. That should pretty much burn off any build up of deposits. I'll do that on the way to the smog shop so that when I get to the smog shop even if the car sits for a little bit it should still be up at operating temperature. I've had good luck when doing that on the way to get smogged and have never been anywhere near failing numbers (that's with having only 1 High Flow Cat in the system).

YMMV

 

OEM cats for CA are REQUIRED to work for at least 7yrs per CARB; as well as:

I have had two cars that were WELL over 7 years on the original cat and both passed emissions without issue.

 

Drive the pics out of it and take it again! You can also throw some e85 in the tank

 

putting this in bold and caps so everyone sees,

1 GALLON OF E85 WILL GET YOU PASSED SMOG!

posted this in the last smog thread, I've already gotten 3 cars that failed on HCs to pass by just adding one gallon of E85, you want about a 1:10 ratio to gas. I got my 84 GTI, 79 Porsche 911, and 98 2.5 RS through this way, DO IT!

 

1 gallon of e85 will get you passed smog!

 

pumped 1.5 gallon of E85 in on saturday, went in today for a retest and 15mph were at 40 max 49, but 25 mph was at 35 max 33.