SMOG.. . Heeeeeeelp!

James Scott · #1 06-04-2009, 11:08 AM

Well... . I failed my first smog test (Test Only) about two weeks ago by having excessive HC >> about 170 MEASURED with 100 being MAX. After I left, I realized I had left my SmallCar (?) Computer Chip wire switch to ON (12 Volt power to help with running regular gas) .. . plus I was using regular gas. I thought this was the problem mainly (hopefully), so I ran Techron cleaner, Berryman's injector cleaner, and Guaranteed To Pass cleaner through my engine with PREMIUM GAS prior to re-running smog test.

I also worried that I had changed my fuel pressure regulator about six years ago, when I was "preparing" to try nitrous (to beat my wife in her 2002 35th Anniv. "haul-ass" Camaro.. . Ha!). I couldn't remember if I left the increased pressure (Impreza) regulator in place (I thought so.. . so I relaced it with what I think (??) is the svx regulator before re-running the smog test). I posted a thread here about anyone knowing how I could deduce which regulator was which, based on the numbers on each (they look identical), but noone responded.

I took the smog re-test a couple days ago.. . the results were worse! I ran the test with the computer chip wire switch off and with premium gas. The HC's were now 265 (instead of 170 first test) with the MAX allowable being 100. HELP!

The only suggestion my friend could give is to try replacing O2 sensors (?). I ordered them out of frustration (they are at least 40 to 60K miles old) for $240 from SubaruParts.com.

Please offer any suggestions to help. California smog can be a NiGhTmArE!

1) Are the O2 sensors likely to help?

2) I guess I should run the next test with regular/switch ON, right?

3) Any ideas how I could determine which regulator is the SVX? Would it even be a problem if I used the Impreza (higher pressure) regulator?

4) HELP!

Thanks!

SoCal LS-L · #2 06-04-2009, 02:43 PM

Since its cheap, replace your fuel filter to make sure you have the best fuel pressure possible, and run your car on the freeway for at least 30 minutes to an hour to really get the cats and 02 sensors hot and clean out your combustion chamber. Your readings are resulting from an incomplete fuel burn it looks like, and the best time to smog an older car is right after a good high speed freeway run to heat it up well and burn out combustion deposits.

NiftySVX · #3 06-04-2009, 09:19 PM

Theoretically, the higher fuel pressure regulator should cause a richer mix, but the oxygen sensors should see it and then the computer should lean it out, but who knows if that actually works.

longassname · #4 06-05-2009, 10:18 AM

Hello Jim,

Your Smallcar chip is actually an ECUtune chip. I made it. Smallcar is one of my resellers. You should not use the impreza fuel regulator with it. The tuning of the ECUtune Stage1v# is for the originial equipment fuel pressure regulator. The part number on the OE regulator is 22670AA050.

Possible/probable problems are:
1)bad catalytic converters
2)bad temp sensor (not the one that sends to the gage..the one that sends to the ecu)
3)missfire
4)leaking fuel injector/fuel injector o-ring

You probably aught to feel a missfire if that is the case.
The temp sensor is the easiest thing to check and cheapest to replace so I would start there just because wouldn't it be nice if that is it?

The temp sensor for the ECU is the one with the plastic plug and two prongs. It is on the water pipe on the top of the engine (next to the other temp sensor which runs the gage) on the driver's side. With the engine warmed up the resistance between the two terminals should drop down to below .3 or .4 Kohms. If it does not then you have a bad temp sensor.

SoCal LS-L · #5 06-05-2009, 11:25 AM

Quote:

Originally Posted by NiftySVX

Theoretically, the higher fuel pressure regulator should cause a richer mix, but the oxygen sensors should see it and then the computer should lean it out, but who knows if that actually works.

As far as I know, lowered fuel pressure causes injectors to squirt instead of spray, keeping the A/F mixture from combusting completely and exhausting lots of HC.

James Scott · #6 06-06-2009, 10:33 PM

Michael: Thanks for the info...I couldn't remember ECUtune..ya!..That's it! Well, then:
1) I hate cats! I've replaced too many..and they're expensive. The main one has clogged twice I think..after banging on the ground [drop springs]. How would I know it's a cat problem?

2) Can I get at the temp sensor easily..without having to remove the intake manifold? Can I get at it to remove if necessary also without removing intake M? So... I test ohms on a warm non-running engine with the connectors off?
3) Missfire??? You mean plugs? Could they need replacement after only about 15K miles? What else could I check that causes misfire? [Maybe it's burning oil??]
4) How would I know the injector(s) was (were) leaking?

Can I FIX something and then check just the idle HC emissions somewhere (smog station or regular mechanic?) before spending another 40 or 50 bucks to perform smog test (and risk referree)?

Thanks for your help! Jim

longassname · #7 06-06-2009, 11:07 PM

well failing emissions is one good sign of bad cats...lol

you don't remove the temp sensor and don't have to remove anything to get at it.

there are many possible reasons for a missfire..start with the temp sensor and assume you don't have a missfire for now though if you put the wrong plugs in it certainly wouldn't help. You should be running the OE spec'ed ngk double platinums. If you aren't that could be part of your problem.

a fuel pressure gauge hooked up between the fuel filter and engine should hold pressure a long time after the engine is turned off. If pressure drops down quickly after turning the ignition off then you have a fuel leak.

Quote:

Originally Posted by James Scott

Michael: Thanks for the info...I couldn't remember ECUtune..ya!..That's it! Well, then:
1) I hate cats! I've replaced too many..and they're expensive. The main one has clogged twice I think..after banging on the ground [drop springs]. How would I know it's a cat problem?

2) Can I get at the temp sensor easily..without having to remove the intake manifold? Can I get at it to remove if necessary also without removing intake M? So... I test ohms on a warm non-running engine with the connectors off?
3) Missfire??? You mean plugs? Could they need replacement after only about 15K miles? What else could I check that causes misfire? [Maybe it's burning oil??]
4) How would I know the injector(s) was (were) leaking?

Can I FIX something and then check just the idle HC emissions somewhere (smog station or regular mechanic?) before spending another 40 or 50 bucks to perform smog test (and risk referree)?

Thanks for your help! Jim

NiftySVX · #8 06-08-2009, 12:22 PM

Quote:

Originally Posted by SoCal LS-L

As far as I know, lowered fuel pressure causes injectors to squirt instead of spray, keeping the A/F mixture from combusting completely and exhausting lots of HC.

I agree, but didn't he say he put a higher pressure regulator in?

Here in oklahoma we don't have smog tests. We don't even have safety inspections anymore. We don't care about the planet or safety these parts.

James Scott · #9 06-08-2009, 05:43 PM

OK! I'm moving to Oklahoma! [Which way is that?]

Sorry...the reading was .246 (on the 2K scale).

I hate these #*%*#@ smog tests AND AL GORE!

I have no idea how I fixed this 2 years ago, nor does my mechanic.. . I'm an idiot! [Maybe it was the gas pills that ruined my relatively "new" cats?? I replaced all three 9/05, but it seems like I had to replace a broken large cat (drop springs - hits) which killed performance about 2 years ago (But, I don't have any receipt for that either?) Does anyone remember the gas pills I started to sell? Ha!]

Help!

Thanks, Jim