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Discussion Starter #1
Hey guys,
I did a search and I could not find anythign similar to my problem for an MKIV. I am BPU++ and I swapped out my downpipe for the cats yesterday. I heated up the cats and FAILED the test. The cats are fine and I passed that part; I failed another part. I wanted to see if anyone could PLEASE help me and make some reccommendations. below are the details of why I failed.
25/25 test 50/15 test

HC-PPM 355 297
allowable 117 120

CO 8.21 6.70
allowable .65 .67

what exactly does this mean? I passed everythign else and am trying to troubleshoot with the car. please help me in any possible way. my email is [email protected] and my number is 404-808-2989. Any help woudl be greatly appreciated

THANKS!
Tosif
 

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HC PPM is Hydro Carbons Parts Per Million.
CO is Carbon monoxide percent

Where do HC and CO come from? Basically from incomplete combustion. Complete combustion of gasoline would yield CO2 and water and we wouldn't have a problem. But complete combustion isn't feasible in today's engines. So we get unburned hydrocarbons going out the tailpipe along with carbon di- and monoxide, nitrogen oxides (NOx) and various other unhealthy crap.

If you have a fuel controller I'd suggest leaning out. Also make sure your spark is good to help get a complete burn.

Please list your mods so we can help further..
 

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Discussion Starter #3
Thanks... the mods are as follow:
apexi intake
HPC coated stock twins
hks ssqbov
rmm downpipe
hks hyper exhaust system
greddy bcc
hks type s front mount
those are the only mods that i feel would cause a problem

I just routed the hoses back to stock and I think I have a boost leake would that make a difference?

I also am not running a boost controller or AFC as of yet.

the plugs were gapped for BPU but I have yet to check them since I changed them and the oil 2700 miles ago. I usually change the oil every 2-3k .. would changing it make a difference for the test? (when i searched a post said it would but I dont see how/why)

thanks again
Tosif
 

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You said you had cat's, check spark and o2 sensor. If your O2 is not reading correctly from being worn you could be running pig rich.
 

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Discussion Starter #5
Oh yea sorry... i swapped out the downpipe for the stock cats yesterday... right now it HAS CATS on it
 

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Discussion Starter #6
What should I look for when looking at the o2 sensor?... is there a way I can clean it? like by using brake parts cleaner or anything?
 

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Use a voltmeter and check the following:

Engine idling at normal operating temp. TARGET A/FR 2.50 ± 1.25 V

Main heated oxygen sensor Heater coil resistance @68 degrees F = 11-16 Ohms.

I've also heard running 2 bottles of rubbing alcohol in about an 1/8th tank will help you pass.
 
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Damn, Georgia is leanient on the cut-points! Try smogging in LA- you'd probably up and sell your car!
 

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Discussion Starter #10
Thanks for all of your help guys... I am replacing the plugs back to stock gap and testing the 02 sensor. hopefully that will do the trick. I am a little afraid to put rubbing alcohol in my gas tank? Are you sure it is safe? Thanks guys!
Tosif
 

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In The Sonoran Desert
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so I assume you have a the stock MAF? Is your BOV venting to the atmosphere or back into the intake? Without vpc or mapecu or aem, routing the bov to atmosphere causes the car to run rich.
 

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EchoDeDupra
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if you have a boost leak inbetween the MAF and the intake manifold you will run rich.... you could always pressure test the system.

By a pvc end piece for the diameter you need. For my car, I need 2.5". Then buy a fitting for an air compressor (hopefully you have one). Tap it into the end piece, and you should be good to go.

Disconnect the pipe from the turbo's and put the end piece there. Hopefully your compressor has a way to control how much air you are using. I pressure tested mine to 25 psi, and I found an egr leak. It turned out I was missing a bolt. Good luck.. and let us know what you find :)
 

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My soultion. Make sure you run the fuck out of the car before you put it on the dyno. My M3 failed. I took it around the block at full throttle 3-4 times and it passed and then some.

The cats need to be REAL hot to pass on some cars. That's when they get efficient.
 

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Discussion Starter #17
I PASSED!

Thanks for all the help everyone! I used everyone's suggestions and advice and it really helped me out. I changed the plugs and gapped them back to stock. and put some fuel additives in the tank and it did the trick. Again, Thanks a lot guys!:D
-Tosif
 

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Discussion Starter #20
DAMN ALLEN! now you tell me haha
Thanks man... I will keep that mind, we need to chill sometime
- Tosif
 
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