So I just went to smog…FAILED, Advice?

[schröe30er]

**Edit: It was the CAT like I said. Btw, for our cars, you can use any CAT in the 36000 series. So if you Cali guys are having a hard time finding one because we are only allowed to search by our year model, and you have a custom exhaust system. You can choose any one from that series that matches your inlet/outlet layout and diameter, and you will still be 100% legal. Whether or not it says BMW in the Application list. All the CATs from the 36000 series are tested on the same vehicle by CARB. It took three pages on here and still couldn't get an answer to that question...too funny. Plenty of engine tuning advice in this thread though, if you need that...read on.



Hello Gentleman,

So I just went for smog and failed...royally too. I failed the whole entire 15mph test, by a high margin. At least double HC and CO, along with high NO. Car has zero engine mods. I put a rebuilt head on it over 2 years ago and I had already passed smog once since then.

Before the test, my car was only sitting for about 6 months while I worked on it. Considering the high numbers across the board, I figured it was the cat, the smog guy agreed.

Question, what is the cheapest CAT I can get away with? Im not worried about CARB compliance, they don't even check that. All I care about is that it will actually work to pass smog. California people only please, unless your a CAT pro.

I am desperate guys, I've been out of work for a year. I just borrowed like $500 to get my car finished and rolling. I have a job lined up once I pass smog. I went to the California Consumer repair assistance program website (CAP), and they aren't accepting new applications until after July 1st. So I am fucked basically, unless I can figure something out.

Thanks for any help

[KenC]

Drive the piss out of it and take it in immediately when it's super hot.

[schröe30er]

Drive the piss out of it and take it in immediately when it's super hot.

I did that, would a cold cat alone cause such high numbers though? I failed by a lot...

15mph test...

HC MAX 108 MEAS 207
CO MAX 0.50 MEAS 1.01
NO MAX 767 MEAS 1056

[Robotin]

pay to pass...

[KenC]

A cold cat will give you high numbers. Find a place that doesn't have a line and can do the sniff immediately when you bring it in. Run the hell out of the car and make sure it's super hot.

[schröe30er]

pay to pass...

I'm down, Where? You can PM me...

[schröe30er]

A cold cat will give you high numbers. Find a place that doesn't have a line and can do the sniff immediately when you bring it in. Run the hell out of the car and make sure it's super hot.

Right, but that high?

Anyway, aside from CAT, I understand what needs to be done to help pass smog, I've searched all that before. This thread is mainly about finding the cheapest CAT options for a single piped exhaust in Cali. I'm going to give her a complete tune up and re-test before I get a new CAT either way. I am just preparing for a worse case scenario.

I read that aftermarket CAT's don't last as long, but I'm not worried about that right now. I can save up for a better Cat later. I just want to know the cheapest one that will work at least once.

[bernzpeed]

Have you heard of CRC "Guaranteed to pass smog" I used it on a newly rebuilt engine at 50miles only, it passed with flying colors. The car was non-op for 3 months.

[schröe30er]

Have you heard of CRC "Guaranteed to pass smog" I used it on a newly rebuilt engine at 50miles only, it passed with flying colors. The car was non-op for 3 months.

You know what I have heard about that stuff, from what I can remember many people have had success with it. I never really looked into it though, going to now...thanks!

Edit:
After just reading the Amazon reviews, I may be sold on that stuff. Ill get the tune up first and see what happens. I do prefer to know whats going on rather then mask it. But at this point I am down for masking. With summer coming up, I need this job, and my vert!

[MR 325]

If your car still has the OEM cat I'm willing to bet it's not bad. Saying the cat is bad is everyone's solution to not passing smog. Have you checked your plugs? Cap and rotor? Valve adjustment? How old is the gas in the car?

[schröe30er]

If your car still has the OEM cat I'm willing to bet it's not bad. Saying the cat is bad is everyone's solution to not passing smog. Have you checked your plugs? Cap and rotor? Valve adjustment? How old is the gas in the car?

Definitely not the oem CAT for this car. It was switched to a
2.5in single pipe before I bought it. I guess it could still be a
BMW made CAT, but I doubt it.

I just had the exhaust off for other work, and the cat has a date
stamp on it of 2/06. So I am guessing its probably nearing the
end of its life cycle? I heard 6-8 years right?

Gas is new. New Spark plugs, Ignition cables, Cap/rotor installed
less then 2 years ago when I did the head, valve adjustment was
also done. All these things have seen minimal use in that time, less
then 1k miles. My WVO benz is my DD.

I think it may be a mixture between the CAT and maybe I need
to change the oil from it sitting. A new O2 sensor wouldn't hurt
either. I'm only replacing the cat as a last option.

[MR 325]

If it's got a cheapo aftermarket cat (and it likely does) it's probably bad.

[oldmann]

My problem was a combination of air inlet temp sensor, coolant temp sensor and 02 sensor. Have U pulled codes yet? New plugs and remove the air cleaner too wouldn't hurt.

[schröe30er]

If it's got a cheapo aftermarket cat (and it likely does) it's probably bad.

Yea, that's what I was thinking.

My problem was a combination of air inlet temp sensor, coolant temp sensor and 02 sensor. Have U pulled codes yet? New plugs and remove the air cleaner too wouldn't hurt.

Yea I'm going to check for codes later today. Ill check the sensors as well.

[schröe30er]

So I did a stomp test, 1444/no errors. So I am leaning closer to the cat. Would an oil change after it sat for 6 months, make a hug difference in the numbers? I haven't used the oil in there that much. So it can't be that dirty.

I'm going to search around for a cheap cat that will work in Cali. Ill get a better one later, and just take the smaller hit now. I just need to get rolling.

If the Magnaflow's are the cheapest option, I may give that CRC stuff a try first...cringe :oops:

Edit:
I'm usually not so cheap...