Failed etest :(

buzzdmonkey · 04-24-2013, 12:12 PM

alright guys well heres my problem. I went for an etest last night expecting to pass pretty well since i installed a brand new O2 sensor and had no more check engine light. but i noticed after the O2 sensor i have a decrease in power

.

so what i failed(so the guy said) even though the sheet says (valid) next to the numbers on was Dilution Percent, it was supposed to be no higher than 6... mines at 14.06 at 2500 RPM and on idle its at 13.61 . i also failed on HC(ppm) whatever that is, the limit for that one is 200 and at 2500 rmp i got 67 so that passed but at idle i got 448! Captaine34 told me how to fix that. SO what i think the problem is is my CATs , i was driving for a while with a broken O2 sensor and i read on bmwe34.net that could have made carbon diposits in the CATs . so before i replace the CATs or make whole new exhaust i just want your guys opinion because im sure theres a few people who understand these numbers more than i do or have had the same problems Thanks in advance

SamE30e · 04-24-2013, 11:10 PM

HC Is hydrocarbons. It's unburned fuel, so either a misfire (which would be obvious) weak spark, bad compression, bad fuel spray pattern (pressure or clogged injector).

If the O2 was replaced then that shouldn't be the issue. Check the vacuum line to the fuel pressure regulator.

When were the plugs done last?

When was the air filter done last? Can you see light through it?

There's a few things that may help.

everlast · 04-25-2013, 02:32 AM

Change the oil too, contaminated oil can blow higher HC.

captain E34 · 04-25-2013, 11:41 AM

give your car a vacume leak and it will lean out ur a/f ration.... you should pass then

buzzdmonkey · 04-25-2013, 09:24 PM

passed!

captain E34 · 04-25-2013, 09:25 PM

Vac leaks, and a chill etester, is a guarenteeeeeed pass

Barnsdale · 04-25-2013, 09:59 PM

What did you have to do to pass?

buzzdmonkey · 04-25-2013, 11:35 PM

Well I made a vacuum leak so it runs richer . Or more lean I can't remember haha . Captaine34 will let you know. But the real reason I passed was cuz I told the guy it was my second time so he made me pass

Robb · 04-26-2013, 12:19 PM

Quote:

Originally Posted by buzzdmonkey

Well I made a vacuum leak so it runs richer .

A vacuum leak will make it run more rich. More air = more fuel.

everlast · 04-26-2013, 12:44 PM

Quote:

Originally Posted by Robb

A vacuum leak will make it run more rich. More air = more fuel.

Nah, the leak will be unregistered to the ECU. So the additional air isn't offset by the ECU as additional fuel: leaner.

SamE30e · 04-26-2013, 05:57 PM

Quote:

Originally Posted by Robb

A vacuum leak will make it run more rich. More air = more fuel.

What.... The.... ****?

No...

bmwconnect · 04-26-2013, 12:02 PM

Running lean will not help, In fact it will drive up readings and fail badly . Running at 14.7 which is stoich for regular gas is the best way to pass

captain E34 · 04-26-2013, 12:22 PM

The problem wit my car and buzzedmonkeys car was that with x amount of air being measured to much fuel was being delivered... small vac, un measured of course, leans out the air/fuel ration and made both out vehicels pass

wether or not its supposed to make it fail... they both passed

captain E34 · 04-26-2013, 12:56 PM

exactly and i have the etests to prove it

first one went to see if it would pass as is..... fail..

etest.jpg

second one, swapped o2 sensor..... still fail....

etest2.jpg

thrid one i found a vac leak, and repaired it...failed worse!!...

etest3.jpg

Last estest, made the vac leak larger... PASS!

etest4.jpg

everlast · 04-26-2013, 12:59 PM

Did you find that technique in the brochure "My Vehicle Didn't Pass the Drive Clean Test"? LOL.. page 3, in case of home made turbo system, induce vacuum leak.