The results

[black98]

Went did my emissions today and I failed CO readings 15.26 and Limit 15.0 real close on this one and the other one i failed was the NOX which was real high reading 2.09 and limit is 1.50 any sugestions on how to get this down I do have a cel on and the emissions read the cel and told me i had code 0505, 0340, 1174. I have ten days to get it retested. So i am going to start with the 02 sensor and clean out the ICV valve and put a new temp sensor in. Any other suggestions would be great.

[teetime4one]

super unleaded fuel couldn't hurt.
or, register your car in Weld county...they don't require emission testing.

[black98]

I know i wish i knew someone in weld county

[black98]

Oh by the way the o2 sensor passed but i am still changing it out cause it looks like it has never been replaced and i have 210000 miles on the car, the cat passed also

[cooljess76]

O2 sensors are expensive, use OEM Bosch sensors with the correct plugs, not the ebay style that splices in. If your car is a 98 like your username suggests, you'll have two o2 sensors. Personally I'd try the seafoam treatment BEFORE replacing the o2 sensors. Dump a whole can in the fuel tank with at least 8 gallons of fuel, half a can in the oil, half a can through the intake manifold via the brake booster line, let it sit for about 15-20 minutes and drive it around until it stops smoking. After about a hundred miles, change the oil, fill up with premium gas. Drive it around and let the catalytic converter get really hot right before you bring it back for retest.

[black98]

I got a bosch sensor this evening from the part store and a can of seafoam. this weekend i am going to do this and test on monday if all goes to plan it should pass

[black98]

do you have a picture of which line you are talking about on the brake booster,

does anyone know what the code 1174

[cooljess76]

Originally Posted by black98

I got a bosch sensor this evening from the part store and a can of seafoam. this weekend i am going to do this and test on monday if all goes to plan it should pass

Which sensor are you replacing, the pre-cat or the post-cat? It doesn't really make sense to replace just one of them, especially if it's not throwing a code and you're just guessing it's faulty. Also, if you're going to do the seafoam treatment, you really should do the complete treatment(2 cans) and do it before replacing the o2 sensors as not to gunk them up or foul them. Just a suggestion, it's your car.

[black98]

both sorry didnt mention that, yep started the seafoam tonight with a full tank of gas and a full can in it also. next tomorrow is the half in the oil and a quarter in the brake booster line, but i am not 100% which line it is on these cars so i was hoping maybe you can clear that up for me

[ZEK]

I've never done a full seafoam treatment, however this article should help you out on the location of the line you are looking for: http://www.318ti.org/forum/showthread.php?t=9408

[hotmilk400]

If you were failing only NOX, it would be the Catalytic converter (it converts NOX (NO to N2), CO to CO2, and and HC to H2O (water).

It looks like the cat converter is working, but to change Nox gas into safe gas, the cat converter needs more O2.

your O2 sensors are probably bad (as mentioned above). if the system is not getting enough gas, the NOX gas output will be high, and the fuel being inputted into your motor is not getting enough O2 to burn 100% (hence why you have high CO2 output as well)

It should be safe to just replace the O2 sensors, but if feel you are mechanically inclined enough to try seafom and are not scared of destroying your motor by doing it wrong (or putting it back together wrong), then go for it. the sea foam will clean up the insides pretty nice. after you dumb in the sea foam, replace the O2 sensors.

but to be honest, if you are not feeling risking, the O2 sensors alone should be okay.

[bullmand]

Originally Posted by black98

do you have a picture of which line you are talking about on the brake booster,

does anyone know what the code 1174

Found this for 1174:
This is a fuel trim code, most often caused by an intake air leak or possibly a failed mass airflow sensor. Unmetered intake air leaks allow excess air into the engine and cause the fuel/air mixture to go out of alignment and cause this code.


With mileage that high it's probably the vacuum lines to the injectors unless you've changed them already. This and the o2 sensors could be the cause of all your troubles since the computer's not getting good data with which to adjust the fuel trim. Also check the intake bellows between the airbox and the two throttle bodies. There's also a large vacuum line that runs from the bottom of the bellow to the main throttle body that runs underneath the upper half of the manifold. That goes to the "distribution piece" attached to the injectors.

Part number 2 and the hoses attached to it are what you really want to check.

http://realoem.com/bmw/showparts.do?...16&hg=13&fg=15

[black98]

Update: Just seafoamed the hell out of the car, cleaned the ICV valve with seafoam also. Did a test run around the block, 15miles at 55mph and a few stoplights she idles perfect never knew that it could be so smooth, doing the oil change tomorrow and then finishing up the tank of gas this weekend and then putting 91 in on monday and then do the retest hope all goes well

[black98]

thank you everyone for you help and info it has been great

[cooljess76]

For anyone else having trouble passing emissions or interested in Seafoaming their engine, here's a link to my thread which includes pictures of the intake vacuum hose:

http://www.318ti.org/forum/showthread.php?t=16181

And here's the results from my California emissions test (Note the HC and NO are measured in parts per million and my results are in red):
http://www.318ti.org/forum/showpost....2&postcount=30

Also note, The "maximum" and "avereage" are for the whole state of California. The measurements that my car produced are colored in red.