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Old 08-24-2011, 09:53 PM   #1
kyleyap
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Default More emissions problems

So my car still won't pass local emissions. I just changed the oxygen sensor and it helped a little bit but I just failed on nox and hydrocarbons. I'm working on getting the robs tune, hopefully that helps.
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Old 08-25-2011, 09:16 AM   #2
TommyAtomic
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Are your cats still good? Do you still have all of them? . Have you checked your a/f on a wideband?

Basicly when combustion occurs in the correct a/f ratio a certain amount of heat and exhaust gasses are created. To the best of what i remember the a/f ratio should be set by the ecu based on the readings maf and the o2 sensor. If the maf and the o2 sensors are good then the a/f should be correct and the cats should be able to get you clean enough you should pass.
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Old 08-25-2011, 01:59 PM   #3
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here in Ontario I go to smaller shops that can't hook up AWD cars so I only have to do two speed idle test... hard to fail that unless something is super wrong.

plugs, oil, cats, gas, all factor into your emissions.
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Old 08-25-2011, 09:49 PM   #4
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well i got new iridium plugs, new bosch o2 sensor, and the coil pack conversion. Ive removed the downpipe to check the cat and its still there and in ok condition. ive cleaned the maf. ive tried testing the emissions with a stock bypass valve instead of the VTA bov i have and that didnt work. some one suggested that i switch to a stock fuel pump instead of the walbro that i have, even though i dont think that would make a difference i tried it anyway and that also didnt help. my insurance is almost up soon and i dont wanna just change a crap load of stuff unless i need too.
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Old 08-25-2011, 09:50 PM   #5
kyleyap
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i was thinking about trying a stock downpipe with 2 cats but that means i need the whole turbo back exhaust
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Old 08-26-2011, 11:29 AM   #6
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what test are you failing? and by how much?
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Old 08-26-2011, 11:32 AM   #7
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also, have you tried running a bottle of seaform through the motor? 1/3 in the gas tank, 1/3 in the motor and 1/3 in the intake manifold (I pulled the BOV vac line and let it suck the fluid out of the can)

you'll be puffing *ALOT* of smoke for about 10-15 mins but it really does clean out the motor.
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Old 08-26-2011, 11:47 AM   #8
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on my last attempt i failed on hydrocarbons and nox. This was the first time ive failed on nox though. I have seafoamed it and there was quite a bit of white smoke
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Old 08-26-2011, 12:02 PM   #9
luka
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NOx is usually because the motor is running hot -- have you done a coolant flush/thermostat lately?
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Old 08-26-2011, 12:25 PM   #10
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and which test are you failing? idle? ~2000rpm idle?

I have a 92 EJ20G w/ 3" turbo back,one hi-flow cat, and rob's 550 tune and I passed against 93 1.8L NA numbers. just barely though, I blew 99/100 and 200/210 for nox/hc so if you're failing something is really wrong.
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Old 08-26-2011, 12:25 PM   #11
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i have done a flush but have not changed thermostat. this is the first time its failed on nox and it only failed by a little bit so im not that concerned. Im mostly worried about the hydrocarbons.
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Old 08-26-2011, 12:26 PM   #12
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ill upload a copy of the test results to show you
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Old 08-27-2011, 01:26 AM   #13
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Old 08-27-2011, 01:28 AM   #14
kyleyap
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first picture is the most recent attempt and so on
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Old 08-29-2011, 02:57 PM   #15
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what did you do differently between the CO fail and then NOx fail? your CO/HC dropped significantly and your NOx went up significantly...
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Old 08-29-2011, 04:15 PM   #16
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I swapped out my walbro fuel pump with a stock one and changed the o2 sensor
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Old 08-29-2011, 04:57 PM   #17
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I think this has been asked but what is your A/F reading? Proper A/F is manditory for clean combustion. The closer the A/F ratio is to a stoichiometric ratio of 14.6 : 1 the hotter and cleaner the burn. In subaru's, I dont think A/F should go nearly to 14.6; I believe we want closer to 11.5:1 or 12:1. ALSO The higher the combustion temperature of the burn the more NOx is created. This can sometimes be compensated for with more cooling or more fuel. Changing your fuel can also help. It may be worth running a tank with 10% ethanol. Ethanol has less power and kills mileage but makes cleaner combustion.

SO, Until you check out your A/F then the only other thing to do is look at cooling things down. What's your coolant temperature and oil temp look like? How close to 185* is your coolant? That should be the goal.

Also are you absolutely certain that your in closed loop?
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Old 08-29-2011, 05:55 PM   #18
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yeah, sounds like you're running leaner if the heat (NOx) went up... maybe put the walbro back (I know it's a PITA) or if you can get your hands on an adjustable FPR...
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Old 08-29-2011, 10:31 PM   #19
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when i had the car on the gas analyzer it shows afr which was around 14.5 ish which is where it should be from what i hear. Im not 100% sure its in closed loop, i always just assumed it was switching over after a while. Any way of confirming? and as far as the nox, im not too concerned seeing how that was the first time ive failed and it wasnt by a whole lot
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Old 09-01-2011, 01:05 PM   #20
TommyAtomic
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Quote:
Originally Posted by luka View Post
yeah, sounds like you're running leaner if the heat (NOx) went up... maybe put the walbro back (I know it's a PITA) or if you can get your hands on an adjustable FPR...
My stock jdm oem fpr was junk and not holding proper fuel pressure. I had idling issues and starting issues. I replaced the old hard cracked crappy vacuum line that drives the fpr with a handy silicon line. That helped me a tiny bit but it wasnt enough so I replaced the origional oem fpr with an aeromotive 1to1 rising rate fpr. Night and day differience.

I only went with the aeromotive because I couldnt find an oem fpr anywhere. Back when I did mine the dealership said it would be a 4 week wait to order one in. Its possible the dealer parts departments have pulled their heads out of their asses since then. The part is exactly the same as on an 02 wrx.

When you were tuning things up and did the coils and threw in the walbro.... if you noticed a differience from the walbro it was probably the higher volume fuel pump compensating for a screwed up stock fuel pressure regulator.

Perhaps someone more knowledgeable about tuning might chime in and mention what A/F ratio you should run to be reasonably emissions clean.
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Old 09-01-2011, 02:02 PM   #21
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Tommy,

what did you set the baseline PSI to? and was that with or without the vac line connected? I got a turbo smart FPR and the setup said set your base PSI without the vac line and people quote 43PSI as the base for these cars.. but is that with... or without the vac line?

Quote:
Originally Posted by TommyAtomic View Post
My stock jdm oem fpr was junk and not holding proper fuel pressure. I had idling issues and starting issues. I replaced the old hard cracked crappy vacuum line that drives the fpr with a handy silicon line. That helped me a tiny bit but it wasnt enough so I replaced the origional oem fpr with an aeromotive 1to1 rising rate fpr. Night and day differience.
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Old 09-01-2011, 11:03 PM   #22
kyleyap
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i checked my water temp with evoscan and it was around 88ish, pretty close to what you were saying it should be. I only changed to a walbro pump because my old one died and i didnt notice any changes in the way the car drives after replacing the original one. ive also checked the fuel pressure with a hand held gauge and it was at about 40psi at idle. is the fuel pressure supposed to hold when the car is shut off? because mine bleeds off slowly to 0. Ive just recently tried switching back to an oem fuel pump for aircare because some one suggested it to me and the car runs exactly the same so i don't think there's a fueling problem.
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Old 09-02-2011, 01:20 AM   #23
kyleyap
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Would turning the boost down to wastegate pressure with a mbc be a good idea when I take my car to air care?
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Old 09-02-2011, 10:06 AM   #24
TommyAtomic
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Quote:
Originally Posted by luka
Tommy,

what did you set the baseline PSI to? and was that with or without the vac line connected? I got a turbo smart FPR and the setup said set your base PSI without the vac line and people quote 43PSI as the base for these cars.. but is that with... or without the vac line?
Yes its 43 without the vac line. A rising rate fpr means that the fuel pressure increases from additional load from the engine.
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Old 09-02-2011, 10:38 AM   #25
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Quote:
Originally Posted by kyleyap
i checked my water temp with evoscan and it was around 88ish, pretty close to what you were saying it should be. I only changed to a walbro pump because my old one died and i didnt notice any changes in the way the car drives after replacing the original one. ive also checked the fuel pressure with a hand held gauge and it was at about 40psi at idle. is the fuel pressure supposed to hold when the car is shut off? because mine bleeds off slowly to 0. Ive just recently tried switching back to an oem fuel pump for aircare because some one suggested it to me and the car runs exactly the same so i don't think there's a fueling problem.
40psi at idle is a tiny bit low but seems like it should be ok. The fuel pressure is generated by the fuel pump pushing fuel against the restriction of the fpr. The walbro will do that just fine. It will just provide more consistant pressure at higher rpms and high engine load. The pressure will always bleed off when the fuel pump shuts off.
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