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davericher20 05-29-2013 11:20 PM

Need help diagnosing (e-test content)
Hey guys, I'm trying to pinpoint what the issue is and I need your help.
I replaced the O2 sensor today because my hydrocarbons are through the roof. Maximum is 400 and I'm at 2010.
I'm getting mixed information on if its running rich, or lean.
i pulled a spark plug out and its white, which is an indicator of it running lean.
As far as I know my afm is good, the air filter is brand new, fuel filter is 3 years old, fuel injectors are brand new (rebuilt), the dist. cap and rotor are 3 years old and they look good.
When i pull the dipstick it runs rough and when its back it runs fine, so that rules out a big vacuum leak.
it can't be the cat because it passed in all other areas.
so I'm stuck, i go for another test tomorrow afternoon simply because i changed the o2 sensor and am hoping that is it, but I'm not putting faith in it.
Also with the spark plugs being white, not sure if its good or bad to keep running with them?

davericher20 05-30-2013 10:59 AM

So I called a reputable shop and they said its running rich, the white plugs doesnt mean its running lean, it could just be the crap gas that was in there over the years and the ethanol has taken its toll.
Its a 2 speed idle test so theres no NoX readings.

Any thoughts on what I should start looking at?

TSI 05-30-2013 12:03 PM

Plugs and wires are good?

food 05-30-2013 01:38 PM

High HC usually mean unburnt fuel is present due to a rich mixture. It could also indicate a really lean mixture. Probably due to the mixture being too lean to burn.

What is your CO level like? It may give an indication as to which side of stoich you are on.

Is your ECU chipped? Have you tried swapping it?

P.S. I am not a mechanic nor an expert on this stuff.


The more I think about it the more I think the O2 sensor is the culprit. During the two speed idle test your car shouldn't leave closed loop operation. This means the A/F ratio should be following the O2 sensor at 14.7:1. If the O2 sensor does not fix it I would be looking in the direction of the cat. I do not know how much CO the cat is supposed to reduce. Even if the cat was not functioning you might still pass the CO level at 14.7:1 as it should be at a low level at that ratio.

Hope that helps.

mr ilia 05-30-2013 05:16 PM

I posted my comments to your thread over at Bimmerforums.

Bullet Ride 05-30-2013 05:57 PM

I have my e-test tomorrow. Should be interesting with a schrick 284, no icv and aftermarket vibrant cat lol *drink*

davericher20 05-30-2013 10:35 PM

Thanks guys, i bought a brand new o2 sensor yesterday and went for a test again today, still failed with hydrocarbons through the roof (but less than the first test),
wierd thing is it brought co2 levels higher and failed on that one, my first test passed on the co2.
I'm not sure the condition of the wires and it is not chipped.
Lol good luck steve.

Bullet Ride 05-30-2013 10:42 PM

Are you failing HC at both idle and 2500rpm?

davericher20 05-30-2013 10:43 PM


noid 05-30-2013 10:57 PM

What are you idling at?

Check this "ninja" air leak location:

Bullet Ride 05-31-2013 09:42 AM

Well Dave don't feel as bad because I failed too this morning lol.

I passed 2500rpm with no issues, but the car was just running a bit too rich at idle.

For some reason I thought the idle had to be under 1000rpm though and getting the car to idle smoothly around 900rpm with no ICV the AFR likes to be on the lower end of 14. My gauge was reading around 14.3:1 to 14.4:1 once I tweaked the fuel but it was a bit lower at first around 13.9:1 to 14:1

However looking at my test sheet the limit is 1250rpm. So I'm going to adjust the idle up to 1100rpm and I should be able to get it to idle leaner there, go back and hopefully it will pass.

For reference here are my numbers...


HC 1416 (limit 200) -> Fail
CO 1.01 (limit 1.00) -> Fail
Dilution 13.81


HC 98 (limit 200) -> Pass
CO 0.54 (limit 1) ->Pass
Dilution 14.99

BMe30 05-31-2013 01:39 PM

Bulletride : are you on the rollers or is just a sniff test? What was your afr during the 2500rpm test? Or is that what the dilution means the actual afr

davericher20 05-31-2013 01:52 PM

1 Attachment(s)
Heres my numbers

2nd test was after replacing the O2 sensor

davericher20 05-31-2013 01:59 PM

1 Attachment(s)
Ipad is retarded

Bullet Ride 05-31-2013 02:04 PM


Originally Posted by BMe30 (Post 1612657)
Bulletride : are you on the rollers or is just a sniff test? What was your afr during the 2500rpm test? Or is that what the dilution means the actual afr

It was a 2 speed idle test, no rollers. I thought dilution might have been the AFR because the values I had were fairly close to what my AFR gauge was reading during the test but it's actually just a measurement to verify that the sniffer is seeing enough exhaust gas to get accurate readings (a.k.a you can't just leave it outside of the exhaust pipe for the test)

My AFR during the 2500rpm test was around 15:1

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