1997 e38 failed smog in california.

[Stereoman]

Well as I see from similar posts i'm also finding out just how much of a pain ca smog checks are. I took my 97 740il in for its first smog so i can register it and get all legal from Texas. Well i failed and whats odd is, why it failed so bad at 15 mph and passed great at 25. Now here is what i have done and getting ready for the retest. First I have changed oil, filter, filled with 91 octane and added a guarantee to pass additive. I had the car diagnosed and all they could say is the maf sensor was giving them a weird reading and i had lazy cats, The car runs great, i recently replaced all ign coils, and i have visually checked the exhaust system which looks great, no rattles, no discoloration, and i have only had codes pop up when the coil packs died, except after having it diagnosed. So im a little cautious and don't think its the maf sensor? SO getting ready for the retest, once this tank is empty i will refill with 91octane add a booster, and go for a drive prior to testing. I checked the MAF sensor and it appears new, will it not send a code and still be bad? Any info I can get the better, Thanks


My first visit M1 - 15mph rpm 1534- co2% 15.1- o2% .2 - HC Max 44 meas 75 - co% max .44 meas .14 - NO max 386 meas 832 FAIL
M2 - 25mph rpm 1618 - co2% 15.0 - o2% .1 - HC max 28 meas 13 - co% .41 meas .01 - NO max 673 meas 57 PASS

[stamar]

http://www.smogtips.com/failed-high-NO-nitrous-oxide.cfm


http://www.smogtips.com/failed-high-hydrocarbons-HC.cfm


one thing on both lists is the catalytic converter.

I would also use seafoam.

[volac]

Could also be running too rich/lean, not sure if that's a concern, but MAF readings being weird may direct there to be too much/too little fuel-to-air?

Soon enough we'll have no cars in CA at all, as they're/we're pretty strict on stuff like this.

[kornkid8600]

Drive you car like you stole it.
Warm it up then drive it hard for 10 solid minutes, high rpm. schedule an appointment with your smog shop and when you get there don't turn off your car, just get on the rollers right away.

You will pass because your cats will be functioning properly by then. They take some time and heat to be effective.

Also it would not hurt for you to get some electrical maf cleaner and have it cleaned up, you spray it on the sensor let it dry. Takes 5 minutes
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[Stereoman]

Filled up with 91 octane and added booster, warmed the car up, even replaced the MAF sensor after the first retest this morning first test this morning double my nox numbers, replaced the maf sensor and came back down to a little below the the original test. So took it back to where i had it diagnosed and he ran a quick test to see what it was, bad numbers again but he did say the maf sensor was now giving good readings, so after a min he said he wanted to try something, not sure what he did with his tester, reset something or what cause now evap system says not ready, cat not ready, o2 sensor not ready and ho2 sensor not ready, However he ran it at about 2500 rpm for 5 mins and i watched the numbers drop like a rock after a min or two and then he retested at 15 mph and 25 mph and it was AWESOME numbers remarkably low, but he couldnt test because of the not ready status on the damn sensors, so he said in the morning to do the same thing he did before driving then get on the freeway for about 5 mins and to not go over 60 and bring it to him, so well see, NOthing i did before hand did any good.


Does anyone know a Smog station in socal that knows how to properly test my car? I have heard that there are certain ways to test?

[Stereoman]

Well the update is, i Finally passed smog. put my factory maf sensor back in and before taking it in i ran it at about 3k rpm for 4 minutes and it flew though. Thanks to everyone for thier advice i greatly appreciate it.