Running Rich

[isantop]

So I went to have the car smogged today, and lo and behold, it failed. Passing out 4.083 GPM Hydrocarbons (Limit is 1.2) and 100.4546 GPM CO (Limit is 15). NOx was fine.

Looks like it's running way too rich. Any ideas what would cause it to fail so badly?

 

[crash89]

Well your profile is empty and you didnt provide us with any/all modifications that have been made to the car. Pretty hard for us to advise what could be wrong..

 

[isantop]

Well your profile is empty and you didnt provide us with any/all modifications that have been made to the car. Pretty hard for us to advise what could be wrong..

Sorry about that. The car is almost completely stock (according to the PO). It has an Aftermarket BOV (Which I haven't been able to recirc yet; could that cause it to fail?), and that's it AFAIK.

I should also note that the CEL is off, and the only DTC in the system is P1500, which isn't emissions related.

 

[gofer]

The P1500 code gets thrown from a bad alternator, typically, but can also mean a faulty wire(s) from the alternator to the ECU or the ECU itself.

Yes, of course a non-recirculating bov will cause it to run rich.

 

[Boostdriven]

Check out this link it talks about p1500 code and how you can fix that.
http://www.dsmtuners.com/forums/newbie-forum/320888-car-running-wierd-throwing-p1500-p0505-code.html

That could be part of the problem why your car is failing smog test. Another thing could be your bov not being recirculated. I only had to do a smog test once and that was many years ago when I was in California so I don't remember the exact process of it but I do remember then holding steady rpms for a while like 3k or something. Your stock turbo at 3k rpms is spinning pretty fast while at the same time your engines is pulling a lot of vacuum which could cause the bov to be part open. Now when you have that your turbo is pulling more air through the MAF sensor then the engines actually consumes and just blows it out of the bov causing the ecu to think that it needs more fuel. If you recirculate the bov then the air goes back in to the turbo after MAF sensor allowing the MAF sensor to read only what the engine actually consumes. If your car has an original o2 sensor I would recommend replacing that too.

 

[isantop]

I'll check the O2 sensor too. And look into getting the BOV recirced ASAP.

In case it helps, here's the graph they handed me afterwards:

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[isantop]

I'll check the O2 sensor too. And look into getting the BOV recirced ASAP.

In case it helps, here's the graph they handed me afterwards:

You must be logged in to view this image or video.

Fixed this. It was the O2 Sensor. After replacing that (what a PITA, by the way), the readings dropped to 0.7629 for the HC (Limit is 1.2) and 7.3827 for the CO (limit is 15). Still a little rich, but I'll attribute that to the BOV. And at least it passed!