[bachn2324]

Hello, as my title stated, I need some help passing emissions in CO with my e92 335i. I have a cat deficiency code that will hinder me from passing emissions to get stickers. I have trouble installing the DP fix as every time, it gives me a Thermostat fault.

I really do not want to go with a new OEM exhaust system as I plan on modifying it anyways. My last shop could not find anything wrong in terms of 02 sensor or a leak.

If anyone or any shop can help me do this within a very reasonable budget or bypass the ECU fault or avoiding the need to go through a dealership, I would love to work with you. thanks a bunch!

P.S. Would love to get this done before August ends, ASAP

[adidoman]

So you have cat less dps on your car right now and you can't get the dp fix to work?

[bachn2324]

Originally Posted by adidoman

So you have cat less dps on your car right now and you can't get the dp fix to work?

No & that is correct. My exhaust is stock. Downpipes are stock. However the car is reading Cat deficiency codes that I cannot figure out what is causing it, as there is no leak and o2 sensor was reading fine according to my shop.

The other solution was to install the DP fix and do a drive cycle. Upon Installation, my car was reading p0598 which is thermostat error or something in that area.

Also, when I installed the DP fix (do not have JB4, straight to the ECU) there was no cable 23 that needed to remove to plug in my last male connector on my DP fix.

I really am stuck as this car is my daily and I cannot figure out how to fix this without spending close to 3 grand for a new exhaust system just to pass emissions.

[rodent]

PM MilehighM3. He works for BMW in Colorado Springs and is very knowledgeable on these cars.

I assume you are failing since they are seeing you have a check engine light which is an automatic fail.

[adidoman]

Seems like something is wrong with a sensor or electronically, not with the exhaust. Can you pull any codes from it? And usually the dp fix is for people with cat less dps, if you have stock it should run normal.

[bachn2324]

Originally Posted by adidoman

Seems like something is wrong with a sensor or electronically, not with the exhaust. Can you pull any codes from it? And usually the dp fix is for people with cat less dps, if you have stock it should run normal.

Yes, Autozone OBD device pulled up the code p0420/430. Catalytic Converter deficiency bank 1 and bank 2. My shop pulled up the same description, although I don't know what the specific code it would read on a BMW specific OBD device.

[adidoman]

Did they try to clear the codes to see what would happen?

[rodent]

It could be bad 02 sensor unless previous owner gutted the cats or the cats have a hole in them. You can also try to space them out using a spark plug fouler. That sometimes tricks them into thinking its burning cleaner.

[csu87]

what county are you in? Larimer county all i had to do was drive by a sniffer. I put it in neutral and coasted through and had no issues.

[MilehighM3]

Originally Posted by csu87

what county are you in? Larimer county all i had to do was drive by a sniffer. I put it in neutral and coasted through and had no issues.

Neutral is worse. Over ~1500 rpms on decel the dme shuts off the fuel. So it's better to do that than to let it idle fyi.

[bachn2324]

Originally Posted by adidoman

Did they try to clear the codes to see what would happen?

Yes, the code was cleared several times I think, comes back when I'm usually low on fuel but now it's more frequent.

[bachn2324]

Originally Posted by rodent

It could be bad 02 sensor unless previous owner gutted the cats or the cats have a hole in them. You can also try to space them out using a spark plug fouler. That sometimes tricks them into thinking its burning cleaner.

It very well could but my shop said all the o2 sensor was reading fine the last time I got a diagnostic for the codes. I don't know what else could cause it. I bought my car from CarMax so I believe they should've caught any fault unless they're half ass garage mechanics haha

[adidoman]

Originally Posted by bachn2324

It very well could but my shop said all the o2 sensor was reading fine the last time I got a diagnostic for the codes. I don't know what else could cause it. I bought my car from CarMax so I believe they should've caught any fault unless they're half ass garage mechanics haha

When did you buy it?

[bachn2324]

Originally Posted by adidoman

When did you buy it?

sorry for the late reply, but I bought it last year

[adidoman]

Emissions should have been done when you bought it, and it should be good for at least two years

[bachn2324]

Originally Posted by adidoman

Emissions should have been done when you bought it, and it should be good for at least two years

It was, the documentation and everything was there. It's also strange at the fact that my car is 7 years old. Emissions test is required for cars 8 year & older.

Anyways, I contacted MileHighM3 & he got me down to Winslow where his team was very nice & they are carrying out Emissions warranty for my car without any hassle whatsoever. It was indeed a bad cat.

[MilehighM3]

Originally Posted by bachn2324

Anyways, I contacted MileHighM3 & he got me down to Winslow where his team was very nice & they are carrying out Emissions warranty for my car without any hassle whatsoever. It was indeed a bad cat.

Actually they're both bad as you suspected. Thanks again for making the trip down to the springs!

[bachn2324]

Originally Posted by MilehighM3

Actually they're both bad as you suspected. Thanks again for making the trip down to the springs!

Thanks for everything man! I really appreciate you and your guy's help!

Was it the downpipe cats or the midpipes? lol

[MilehighM3]

Originally Posted by bachn2324

Thanks for everything man! I really appreciate you and your guy's help!

Was it the downpipe cats or the midpipes? lol

The cats on the downpipes are the only ones monitored for emissions on your car. So you'll have 2 new ones whenever you're available to have them installed.

[bachn2324]

Originally Posted by MilehighM3

The cats on the downpipes are the only ones monitored for emissions on your car. So you'll have 2 new ones whenever you're available to have them installed.

I'm trying to get Tuesday off, I'll give you guys a call come monday to confirm everything!

[Barrique_Red]

Originally Posted by rodent

PM MilehighM3. He works for BMW in Colorado Springs and is very knowledgeable on these cars.

I assume you are failing since they are seeing you have a check engine light which is an automatic fail.

I do not believe that this statement is true. The check engine light has been on in my '92 F250 for about 6 years now. I pass emissions in Denver Metro area every time.


Do you have a source to back up the above statement?

thanks.

[bachn2324]

Originally Posted by Barrique_Red

I do not believe that this statement is true. The check engine light has been on in my '92 F250 for about 6 years now. I pass emissions in Denver Metro area every time.


Do you have a source to back up the above statement?

thanks.

I believe car at 1992 is subject to the sniff test? I'm not sure, but it could just be an electronic error for your CEL and the car itself is running fine to pass emissions. I don't get how the whole process works, but for cars newer they are subject to the OBDII testing, and if they have the CEL or emissions related code, then you won't be able to pass.