DP pre-cat removal

[LiloGTI]

So I just got a custom straight pipe (starts at the cat) and I just found out that there is a pre-cat in the downpipe. I was wondering if I will still be able to pass emissions testing in Colorado if i remove the pre-cat. Also would a CEL pop up? I am looking to go stage 2 with APR and want to get the most out of it.

 

[flat tire]

You want a 3" downpipe off eBay. You're welcome. Don't gut the stock downpipe.

 

[eurocars]

So I just got a custom straight pipe (starts at the cat) and I just found out that there is a pre-cat in the downpipe. I was wondering if I will still be able to pass emissions testing in Colorado if i remove the pre-cat. Also would a CEL pop up? I am looking to go stage 2 with APR and want to get the most out of it.

If they do a sniffer test (exhaust gas analyzer) or visual inspection of the exhaust, you will not pass. If they only check through the OBD port like most states, you will pass as long as the tune is enabled to set readiness and you have an anti-fouler in place, or have it tuned out. Most aftermarket tuning companies have these features

 

[Epic_Sandwich]

Colorado is fun because for emissions testing OBD-II cars they:

Run the car on the dyno with an exhaust gas analyzer

Perform a visual inspection for the catalytic converter(s) (Had a friend who passed the dyno but still failed because he only had a single aftermarket cat when the car originally came with 2)

And now they just introduced an OBD-II scan for readiness and CEL

You must pass all 3.

So, basically in Colorado, you MUST have the factory downpipe installed to pass and a tune with readiness on. I plan on installing my factory DP for the bi-yearly emissions test and using my DM Programmer to update my calibration for readiness.

 

[LiloGTI]

you're wrong the emissions testing for 2005 and newer is only OBD unless ODB fails then it must be tested on dyn. and most cars do not get visual inspection.

 

[LiloGTI]

They will not dyn unless ODB fails.

 

[golfballer78]

you can get a spare used dp cheap & swap pipes out when necessary if yer worried about it. the cat next to the turbo is the one to get rid of. but if yer swapping pipes for smog, might as well get larger aftermarket catted or not.

 

[Strieg]

you're wrong the emissions testing for 2005 and newer is only OBD unless ODB fails then it must be tested on dyn. and most cars do not get visual inspection.

And where is it you live? I know where I live it's obd, visual, and sniffer.

 

[LiloGTI]

Colorado

 

[Epic_Sandwich]

you're wrong the emissions testing for 2005 and newer is only OBD unless ODB fails then it must be tested on dyn. and most cars do not get visual inspection.

Before calling people wrong be aware that emissions is done differently in the varying counties of Colorado.

Also inspection seems to vary greatly depending on where you go and what mood the techs are in that day. I had a friend just fail inspection even though he passed the sniffer/dyno test with flying colors because the car originally came with 2 cats and he put in a single one with an aftermarket downpipe (Different car, not a VW).

 

[LiloGTI]

It is not different. It is done by the same company and I have worked in two different cities for Air Care Colorado. It is all the same.

 

[LiloGTI]

There is a guide that will tell you what every car has. I'll try to find a link.