Failed SMOG test today

[tvcasualty]

Failed my smog test today. What do you guys think the issue is? Anybody had good luck using denatured alcohol or those guarantee to pass emissions stuff at the auto parts store? I only need this car to pass once.

627756


Car passed back in December so I thought I would pass without issue,wrong.

[Team Neverlift]

How hot were the cats prior to the test? Did you turn the car off at all after driving it and it going on the rollers for the test?

If the cats were hot, I would say you need some new or better working cats to pass.

[mslevin]

Someone who isn't me has experience with this...

Change your oil. Make sure you have like 1/4 tank of fresh 91 octane. Put 32oz (or more!) of 91% IPA in the gas. Get the car really hot and don't turn it off before the test.

You're not far off passing. Most likely your cats are on their way out.

[tvcasualty]

Cats were probably not that hot.....Yeah like a dummy I thought I would pass no problem so I drove straight there from cold. And yes turned car off before test.

The HC is triple the limit on the 15mph test and double on the 25mph do you think I can overcome that??

There is an alternative of course but it is more expensive,but this will be more expensive if I fail a few more times. def not replacing cats on this thing

[Team Neverlift]

My OEM mid pipe is sitting in my garage, if all else fails for you, you can borrow it for the test. I can't make any promises, but it worked when I tested it last year. Haha

Cats are the only thing that could have changed in that time frame, and they take some time to get heat into the both of them. If you are still on the same oil you used at the track, it couldn't hurt to change it, and give Test Station a car with warm cats (15+ mins hwy) and see what happens... but it could also just get worse, tbh.

[Eric93se]

Cheapest is to find your vacuum leaks, put premium gas and use a bottle of CRC GTP. Don't go right to the testing place, drive the car hard (high rpm). Your cats are fine, if you don't pass change your pre-cat oxygen sensor and clear adaptations.

[JDStrickland]

Someone who isn't me has experience with this...

Change your oil. Make sure you have like 1/4 tank of fresh 91 octane. Put 32oz (or more!) of 91% IPA in the gas. Get the car really hot and don't turn it off before the test.

You're not far off passing. Most likely your cats are on their way out.


Not far off? He's got 3 times the allowable HC in the Low Speed test, and double in the High Speed test. The car is running rich, and/or has blown CATs.

[mslevin]

Not far off? He's got 3 times the allowable HC in the Low Speed test, and double in the High Speed test. The car is running rich, and/or has blown CATs.


Compared to my recent fail, nope. Fixed with a similar method.

https://farm1.staticflickr.com/958/26810451577_49686cfcf2_c.jpg

[tvcasualty]

Compared to my recent fail, nope. Fixed with a similar method.

https://farm1.staticflickr.com/958/26810451577_49686cfcf2_c.jpg

Are you telling me rubbing alcohol got that into passing range? Damn. If so that's impressive.

I'm not gonna put a bunch of money or time into getting it to pass but that seems worth a try. I only need it to pass once I'm registering it in an area with no biannual only change of ownership tests. And this car won't ever get sold.

I shot myself in the foot when I bought the car the PO had it smogged 2 and a half months prior I lagged when I finally went to transfer it was past the 90 days.

[gc325is]

FYI HEET the gas additive

MSDS says red bottle HEET is 99% isopropanol = isopropyl alcohol, whereas, as above, yellow bottle heet is 99% methanol = methyl alcohol.

[TheStigg]

Put 32oz (or more!) of 91% IPA in the gas . . .

IPA as in Pliny or Lagunitas?

Seriously though, agreed with getting it hot and a fresh oil change before having it smogged. You could also try a "Shogun reset" (disconnect the battery to clear stored DME settings. I overheated my wife's 1994 325i warming it up too aggressively for a test and it spun the water pump impeller off of the shaft and the temp gauge shot up into the red and the engine shut itself off on the drive home. I put in a new water pump and thermostat and went back for a re-test and it failed HC's. Apparently the DME "remembered" it had overheated and tried to enrich the fuel mixture to compensate. After disconnecting the battery to clear the fault, I took it out and drove it normally on the interstate for about 30 minutes before testing it again, and it passed with very acceptable numbers.

[Deus Ex Machina]

This thread makes me glad there are are no emissions requirements where I live.

[tvcasualty]

IPA as in Pliny or Lagunitas?


Hopefully Lagunitas its cheaper



Im undecided yet whether im gonna change oil clean the MAF put in some alcohol and try to get it to pass or just find a smog tech that likes extra money. I ran Buttonwillow yesterday and hitting Streets of Willow Springs today so if its the cat going it will def be worse. oil only has 2k miles on it feels like a waste to change but its def dirty looking.


one thing i forgot to mention i got a CEL about 2 weeks ago came up as "P1421 secondary air system bank 2" which has to do with the hoover vacuum under the hood for cold starts and the corresponding check valve. I cleared the code and it hasnt come back cause it hasnt been cold i assume. i havent investigated further but lets say the check valve was stuck open and exhaust is escaping that would affect fuel mixture but if anything i would think it would lean it out......right?

[Eric93se]

If its stuck open it will suck in air, so yes it would try to lean out. Simple test is to unplug the large hose from the SAP and blow into it (the one going to the valve), you should not be able to blow through.

[tvcasualty]

If its stuck open it will suck in air, so yes it would try to lean out. Simple test is to unplug the large hose from the SAP and blow into it (the one going to the valve), you should not be able to blow through.

Thanks. tested it thats not the issue. Pretty sure the pump is dead. def not replacing that it was gonna be pulled from the car.

CEL showed up again and I reset it. How many miles do I need to drive till it wont show up on their scan ???

Right now the plan is run some Seafoam through the car, clean the MAF, Change the oil,toss in some alky of some sort and give it one more shot next week.

I hooked up my scanner to see what temp my E-fan is coming on in case that is making it burn less complete...idling before i took off it was coming on at 198 degrees but after a drive didnt kick on till 205. that sound ok?

Would dropping down to 89 octane possibly help??

[Team Neverlift]

I know I have posted this here before, but too lazy to look it up. Miles have nothing to do with it. There is an OBD2 Readiness check list, that has specific driving conditions that must be met before it will allow a test. If you plan it out, it takes a few hours to do right. I'll get more info on the exact procedures tomorrow.

Can't find it, but found this... very similar, explains it better. http://www.instructables.com/id/How-to-Do-BMW-OBDII-Drive-Cycle-For-Smog-Check/

[tvcasualty]

I ran seafoam through the vac line cleaned the MAF put my stock airbox back on again changed spark plugs changed the oil. THen I ran it hard for 30 mins yesterday stopped at my house put in 32oz of rubbing alcohol (gas light was just about to come on) did not turn the car off before the test and here are the results:

628389


Failed again. NOx was cut down to acceptable levels but HC is still high in both tests. Im thinking cats are tired?

The "Tamper" is because this guy tried to claim my air duct missing for the alternator was a fail....wat?? I would have fought it hard if it didnt fail everything else. First place i went to tried to tell me the end of the SAP hose was supposed to be attached to something..... OBDII wasnt ready. I know now I can check that with my scanner before i go back. This time i went to a place with a free retest so I have one more shot.

[LunaVyohr]

I was having similar issues with similar numbers. I replaced, well, everything.

Stop putting chemicals in your gas tank hoping for some magic cure. Sometimes that works but most of the time, it doesn't. It made my numbers worse, actually.

You need to get somebody who can do some real testing. Make sure your O2 sensors are responsive and then check the cats. I had to eventually just bite the bullet and buy new cats -- not as expensive as some people think. You can get universal, CARB legal, Magnaflow replacements for about $160 each on Amazon.

[Eric93se]

isopropyl alcohol has water in it. You should have put a bottle or CRC GTP and PREMIUM GAS, then drove the car hard for a good amount of miles (couple days hard driving).

[JDStrickland]

READINESS MONITORS
When you reset the computer, turn the Check Engine light off, you trigger the Readiness Monitors. There are several systems that go out and check the various sensors and components to see if they are working within the nominal ranges. You must complete qualified drive cycles before all monitors will come to ready. In a perfect world, it should take less than 3 drive cycles, many of the monitors will clear, come to a Ready State, in a single drive cycle. The monitors for the EVAP and CAT systems are typically slow, there are any number of reasons for this to be true. The point is, you will see two monitors that might take several drive cycles. A drive cycle REQUIRES a Cold Engine Start, engine speeds to remain below 3000 rpm, maintained speed of 60-ish for 20 minutes, and a few other parameters. You should google "OBD II Drive Cycle".

High HC is problematic because it means there is raw fuel in the exhaust stream, and raw fuel is detrimental to the CAT. There is a trick to spark plugs, they are available in different heat ranges, and the heat range can affect the complete combustion of the fuel load in the cylinders. I'll let somebody else tell you which way you need to go, but to make the point I will say that a cold plug makes reduced combustion temps, and this creates unburned fuel in the exhaust stream. A hotter plug will give a more complete combustion, therefore less unburned fuel and lower HC. Again, I might have the hot and cold plugs reversed, but the idea is accurate.

If you have a monitor that is slow to come to a Ready state, then this can be an indication that either the system is not working correctly, or a sensor is soft and the input it sends to the computer is at a limit of the allowable range. Let's say that in input needs to be in a range of 1 to 5, and the sensor gives a 0.95 or 5.05 input once in a cycle. The monitor looks for repeated fails, but a second fail does not happen so the monitor continues running for the next drive cycle. Add to this that you might start the car and then park at Starbucks for coffee, the drive cycle is not completed because you stopped too soon but the requirement of a Cold Engine Start is also not met because the restart is a warm engine so the drive cycle aborts for that trip and the monitor starts up again on the next cold engine start. At the end of all of this, the monitor will either finish with all monitors Ready, OR the Check Engine Light will be turned on because something is reported out of range enough times to trigger the light. If all is well and you get the monitors to come to Ready, then it should happen in a single trip, maybe 2. Because of variables you induce, it could take several trips to complete a qualified drive cycle.

[LysanderSpooner]

High HC is problematic because it means there is raw fuel in the exhaust stream, and raw fuel is detrimental to the CAT. There is a trick to spark plugs, they are available in different heat ranges, and the heat range can affect the complete combustion of the fuel load in the cylinders. I'll let somebody else tell you which way you need to go, but to make the point I will say that a cold plug makes reduced combustion temps, and this creates unburned fuel in the exhaust stream. A hotter plug will give a more complete combustion, therefore less unburned fuel and lower HC. Again, I might have the hot and cold plugs reversed, but the idea is accurate.


In all of the emissions related threads I have read, this is the first time I have come across the subject of spark plug heat ranges. Interesting.

I used to build two stroke engines for racing, and choosing correct spark plugs is critical in that application. The main reason being that two strokes fire on every revolution, so the plugs are doing double duty in comparison to four strokes. Add in high compression and the fact that a well designed expansion chamber reverberates unburnt fuel back into the cylinder just before the exhaust port closes at the desired RPM range where peak power is made, and those little plugs are really getting the torture test.

A given plug's heat range is pretty simple to comprehend, it's just determined by the depth of the open space around the white insulator. If the insulator has a deep well around it, it will effectively be hanging out in space with a large air gap around it, which reduces heat transfer from the center electrode into the plug body and makes it retain more heat. This is a "hot" plug. Put in too hot of a plug for your application in it will melt down, often taking the piston out with it.

On the other hand, a short insulator with a shallow well will run much cooler, because the center electrode is physically closer to the plug body and the heat can dissipate more quickly. Too cold of a plug will never get hot enough, causing a rich condition and eventually fouling, particularly in two strokes with oil in the fuel mix.

I am having a bear of a time getting my 740i to pass smog, and I think I am going to find me some hotter plugs. Glad I ran into this thread!

[jclausen]

So are the monitors ready and talk with an local independent BMW shop about who they recommend for smog and what is the smog guy saying about the secondary air hose