Best way to run catted section 1 for CA smog ?

[bavarian3]

I think it’s combination of people wanting completeness, and it’s what everyone is used to from way back.

To me, either way you run euro cats are technically not legal because they aren’t North American factory spec, in the factory location as CA smog requires. So why go through the trouble…. But to each their own. I pass smog and that’s all that matters to me.

Yeah thanks again for chiming in with this. Saved me a lot of trouble. I actually much prefer this route if it works as it's no work to reverse back to OEM.

[L0okitzRaj]

This does make me wonder why we're all going through the trouble of hacking/modifying the harness to run the post-o2's? Just for completeness? Aftermarket cat wouldn't pass visual anyways so can't be that?

I think it’s combination of people wanting completeness, and it’s what everyone is used to from way back.

To me, either way you run euro cats are technically not legal because they aren’t North American factory spec, in the factory location as CA smog requires. So why go through the trouble…. But to each their own. I pass smog and that’s all that matters to me.

[Tbonem3]

This does make me wonder why we're all going through the trouble of hacking/modifying the harness to run the post-o2's? Just for completeness? Aftermarket cat wouldn't pass visual anyways so can't be that?

To pass California smog

[heinzboehmer]

Just for completeness?

Yeah that's why I did it. Didn't sit right with me to leave the system half operational (even though it doesn't really make any practical difference with how I drive my car).

[bavarian3]

This does make me wonder why we're all going through the trouble of hacking/modifying the harness to run the post-o2's? Just for completeness? Aftermarket cat wouldn't pass visual anyways so can't be that?

heinzboehmer Tbonem3 gabylonfive zzyzx85 L0okitzRaj

[gabylonfive]

another data point here - i passed smog with no issues recently with my rear o2s coded out using martyn's tool. stock cats and o2s are installed but i just couldn't get the cat monitors ready and was tired of trying to do the drive cycle.

[174bpm]

I'm running Euro catted section 1 and it passes smog. All O2 sensors are plugged in. The harness was extended so they could reach.

I'm running a Euro section 1with an extended harness as well. Also have a tune. No issues smoging the car last month.

[L0okitzRaj]

Post cat o2 sensors are only for monitoring cat efficiency. So no downsides.

[bavarian3]

You can also just code out the rear o2 sensors using Martyn's tool. It'll still pass, as it defaults the sensors to Ready. That way you can install your cats however you want, no need to reroute wiring.

I'm running no cats and have passed smog on two separate occasions in LA.

Thanks a ton for chiming in with this. If this is the case perhaps I'll just start with that route before modifying anything wiring wise.

That then leaves the question if there's any downside at all to deleting post-cat o2's?

[L0okitzRaj]

You can also just code out the rear o2 sensors using Martyn's tool. It'll still pass, as it defaults the sensors to Ready. That way you can install your cats however you want, no need to reroute wiring.

I'm running no cats and have passed smog on two separate occasions in LA.

[bavarian3]

I think so? Recopied the link just in case.

Post 110 in that thread shows how I did it

now the link works(other link sent me to oil filler caps on pg 3, lol) , thanks =) will read through this.

[heinzboehmer]

Is this linked to the right page?

I think so? Recopied the link just in case.

Post 110 in that thread shows how I did it

[bavarian3]

You can also do it without cutting anything: https://nam3forum.com/forums/forum/m...ge3#post131221

Is this linked to the right page?

[heinzboehmer]

I read about the extra length wire in the sleeve, but it looked like you did things a little differently? Not clear.

And you have no issues with intermittent check engine lights? how about you zzyzx85

You can also do it without cutting anything: https://nam3forum.com/forums/forum/m...221#post131221

[jpy1980]

1. The ecu performs checks each cycle (start to stop). It happens all the time, but there are operating conditions that must exist for the cycle to complete. For example to set the monitor ready for cold start the engine must be cold, and you must not touch the gas pedal for a minute or 2 while sap warms up the cats.

2. Yes. The main issue is quality of cats. Must be good enough to satisfy the o2 sensors (post cat). I've passed smog with ebay, ap euro and supersprint headers and eurocats, ssv1 hjs and magnaflow 200 cell into 2.5' ss v1 decat pipes.

Thank you so much for the response appreciate it!