Failed smog

[SilverBeam]

Posting this for crotchmonster, he just bought a 97 M3 that failed to pass smog. He wants to try some things first before contacting the pervious owner to fix the problem.

the car is a 97 w. 109,000 miles.
JC Shark injector
ITG intake
5/30 sythetic oil

the hydrocarbons were too high. if he removes the software, puts back the stock airbox, and changes the spark plugs, is there a good chance that he'll be in the clear? Or do you think something else may be causing it not to pass smog? (this is CA by the way).

Thanks.

[e30sd]

run some guaranteed to pass. (buy it at any parts store)

fwiw, it's the seller's responsibility to have a smog certification done in the state of CA. did aren get a break on the price or something? i'm wondering why he just didn't do that.


edit: have you checked the O2 sensor yet?

edit x2: correction, have you checked all 4 O2 sensors yet?

[nickdrivesm3]

pm sent

[SilverBeam]

I know its the previous owners job to fix it if it doesn't pass, he just wants to take care of the obvious for a retest first, before bothering the previous owner. He hasn't checked the O2 sensers yet, he isn't getting any codes or check engine lights.

thanks for the PM, I'll get back to you when I know.

[SilverBeam]

pm sent

check your pms

[RotaryBzzz]

You should post his results at both low and high speed testing.

Post the O2 / CO / NO levels as well....

[BimmerBoy]

on my 325 I tested it I failed 2 years ago for the same reason as you failed (but the smog guy was cool enough to let me pass, he was a friend of a friend), this year i had no such hook up because of the dyno smog. I was also in fear of failing this smog because 4 years ago I also failed smog. Well any how. What I did this year was drive my car hard to the smog place, before I got there for about 30 mins, I mean I red lined every gear every chance I had. on top of that the mods I have were intake, exhaust, and chip. Before when I failed my car didn't have any performance mods. Well when I smog my car this time i passed with flying colors, way below the max, and way below what is average. Pretty much, the smog guy this year was another friend of a friend, but he told me that alot of the times, just as long as the cat is good, and it is hot enough, the car will pass. He was telling me that he has had customers that had their cars burn oil and still pass because the cat was good, i understand that you have OBD2 and the smog test for that is more strict, but I would try and see if getting the cat hot enough will help your car pass, if you did drive your car hard before the smog test, then I'm a loss for words. Good luck

[iwannadinanm3]

drive the f*ck out of the car to get the cats really warmed up, with high revs, then take it to the smog station right away, try that out.

[SilverBeam]

THe 15 mph test passed quite easily. But the 25mph failed

%CO2 , %02 , HC (PPM) , CO (%) , NO (PPM)
Test , RPM , Meas, Meas, Max, Ave, Meas, Max, Ave, Meas, Max, Ave, Meas
25 mph, 1886, 13.0, 1.9 , 37 , 7 , 38 , 0.47, 0.03, 0.05, 717, 50, 33

^ that's the read out

[94is]

Hmm, thats weird. My car failed smog a couple weeks ago. It passed with flying colors at 25mph but under load (15mph) it bombed the Nox and was a bit over on the hydrocarbons too. I'm getting the low mileage cats installed on Friday, swapping the airbox on Sunday and will be installing a '94 m3 stock chip too. I'm going to run GTP and drive the piss out of it before they smog it. Oh yeah, and pray. :stickoutt

[LWRNCE]

The guy at AAA passed my car when I knew forsure it wasnt going to pass the visual. How much did you guys pay? I paid $8.75 for the whole entire smog tester stuff.

[bungi]

From previous experience with other cars that have failed the smog test, changing out the O2 sensor worked every time.

[LWRNCE]

Vallejo? What part?

[JLac]

It could be your cats. I failed once with Euro HFM, AA 3.5" Intake, and a matching JC chip. Even after I took those things out, I still didn't pass, the numbers did not change too much. I found that my engine mods did not really change any of my numbers too drastically. To pass the smog, I finally gave in and got new HIGH FLOW CATS. I found out that the inside of my old cats were all cracked and broken. After installing the new cats, I finally passed, but was shockingly on the borderline on every test.

Oh well, at least I passed. :stickoutt

[potomac]

tell him to clean out his EGR valve...that should do it.

[SilverBeam]

**update** car passed, he removed the chip and it passed with flying colors.

[KozanBMW]

Your chip may not be tuned properly for your setup then. I would look into a reprogram, or a new chip.

[RotaryBzzz]

definately change the chip. You'll kill the cats eventually.