I need some advice/recommendations on passing emissions. My 2002 WRX has failed the carbon monoxide test for emissions twice. The readings were 25.3764/25.1095 and the limit is 20 (Colorado). All the other tests passed. Here’s what I have on the car. The engine was hot for both tests.

Test 1
- COBB AccessPort ECU Stage 2, 91 Octane as the base map
- MRT Turbo Back Exhaust with a high-flow cat in the DP
- JDP STi up-pipe
- Walbro 255 fuel pump
- The intake is more or less stock, but the snorkel and the scoop were removed
- The car had more or less a full tank of gas
- Name brand gass, full tank, 91 octane
- Recent oil change

Change for Test 2
- COBB AccessPort ECU Economy 91
- 4 gallons E-85

I have the stock turbo back exhaust that I could install if needed, but I think the car should’ve passed as is. Any ideas what might be causing this? Has anybody else run into these problems? There are plenty of folks who are passing emissions around here with 1 cat.

Thanks – Tim (TIMMAY!)

may be a bit too much extra work, but i would say throw on the stock DP pass with flying colors and then switch back.

I need some advice/recommendations on passing emissions. My 2002 WRX has failed the carbon monoxide test for emissions twice. The readings were 25.3764/25.1095 and the limit is 20 (Colorado). All the other tests passed. Here’s what I have on the car. The engine was hot for both tests.

Test 1
- COBB AccessPort ECU Stage 2, 91 Octane as the base map
- MRT Turbo Back Exhaust with a high-flow cat in the DP
- JDP STi up-pipe
- Walbro 255 fuel pump
- The intake is more or less stock, but the snorkel and the scoop were removed
- The car had more or less a full tank of gas
- Name brand gass, full tank, 91 octane
- Recent oil change

Change for Test 2
- COBB AccessPort ECU Economy 91
- 4 gallons E-85

I have the stock turbo back exhaust that I could install if needed, but I think the car should’ve passed as is. Any ideas what might be causing this? Has anybody else run into these problems? There are plenty of folks who are passing emissions around here with 1 cat.

Thanks – Tim (TIMMAY!)

The only easy things I can think of are a new air filter, and a good Italian tune up run with a high detergent gas, like Shell V-Power, since you still failed with a boat load of alcohol in the tank.

How do they conduct that test? They don't take sniffer readings in Maryland on an 02 WRX. Is it on an awd dynamometer, or a just a probe up the tail pipe.

I'm in the process of putting on the old exhaust and new plugs now. Lame... Hella lame...

Don't feel bad I have to do an engine swap to pass, it's just part of the game you got to pay if you want to play.
MCL

Damn, dude. You win... What has to happen to require an engine swap to pass?

the real question is are you failing the 2 speed idle test at idle or at 2500?

they're still using sniffers out there? if you're engine light's off, you should try finding a place that hooks into obdII port.

Damn, dude. You win... What has to happen to require an engine swap to pass?
It is easier to do a full swap then a part by part "restocking" of the car. Big turbo, big injectors, custom fuel lines, TGV deletes, just a lot of thing that cause CEL's. I got done with it today, only two codes after the swap so far. P0103 Mass or Volume Air Flow Circuit High Input. P0113 Intake Air Temperature Circuit High Input. Cleared them and haven't come back yet, not too bad if I say so myself.
MCL

.....

only two codes after the swap so far. P0103 Mass or Volume Air Flow Circuit High Input. P0113 Intake Air Temperature Circuit High Input. Cleared them and haven't come back yet, not too bad if I say so myself.

That's interesting. I got the same error codes when I disconnected the battery and pulled the MAF. I cleared them and they haven't come back.

Also, I'm not exactly sure what's testing what, but they plug into the ODBII port and they put something over the exhaust. I suppose they could just be venting the echaust?

Its an OBDII scan and a sniffer. However, it is rumored that the sniffer will no longer be required very, very soon in Colorado. I hope the rumor is true 'cause I will have to emission my '04 in '09.