P0420 & P0430 codes at same time with new supersprint cats

[maupineda]

You can try a spacer to expose the 02 sensors less to the exhaust stream. that would lower the reading.

[mcfreid]

Hmm, any sense for how big of a spacer in order to reduce the voltage readings back to normal?

[repoman89]

Deleting the catalyst codes makes no difference for OBD2 smog checks. If you're in CA you'll already fail the visual.

You could try this, hasn't worked for me though https://nam3forum.com/forums/forum/s...ncy-thresholds

[Tbonem3]

The HJS cats are 200 cell, not 400 like stock, so perhaps that's a factor, but I run the HJS and pass smog in CA fine, so IDK.

[repoman89]

The HJS cats are 200 cell, not 400 like stock, so perhaps that's a factor, but I run the HJS and pass smog in CA fine, so IDK.

In my experience the engine software can easily make the difference whether the catalyst codes show up with the 200 cell HJS cats. When I ran stock US software I never got P0420/0430. With a CSL based PCS tune I get it on chill highway drives after an hour or two. Engine control routines can be optimized for some combination of power, efficiency and emissions .. apparently I have sacrificed the latter for power and efficiency. I never saw 27mpg on the stock tune but that’s what I get on the highway now, and I haven’t dynoed the car but it’s obvious it pulls harder.

[mcfreid]

The saga continues!

I had cleared the codes some time back and when I last took the logs, the check engine light was not on.

Today, the check engine light came back on and I started logging again in case there was a difference in behavior. Fortunately I quickly came up to a stop light within a minute of the CEL and got some decent idling data.

The results look quite different than last time: both o2s2 sensors were showing voltage drops. Does it take some time once you start idling for the voltage to settle, or is it expected to be immediate?

[maupineda]

No, once the o2s2 sensors are hot, they should read stable. Seems your cats gramage may not be enough to convert gases.

[mcfreid]

Hmm, anyone else with supersprint cats dealing with this issue?

[CarbonBlkM3]

I ran into this issue a few years back with my Supersprint setup, but if I'm not mistaken I only pulled up code P0430. Installed 2 non-foulers on each post 02 and solved the issue for me.

[Cubieman]

I ran into this issue a few years back with my Supersprint setup, but if I'm not mistaken I only pulled up code P0430. Installed 2 non-foulers on each post 02 and solved the issue for me.

That can work and is cheap, that's what I did on my WJ jeep after I had the cat removed as it was clogged.

You can also get little spacers with a bit of catalyst in them to help them chances, never had any experience with them. Fabspeed (meh) makes a pair that sells for $295 and and then there are numerous similar items for significantly less on ebay/Amazon.

Not much space up there where the post-cat O2's are, I don't know if you could stack 2 spark plug de-foulers and still have room for the sensor itself.

Example of a cheap O2 spacer.

https://www.ebay.com/itm/324589607124?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=xH3bgWD3R6i&sssrc=2349624&ssuid=_wVQTCcTQkK&var=&widget_ver=artemis&media=COPY

[LatinSkllz]

I ran into this issue a few years back with my Supersprint setup, but if I'm not mistaken I only pulled up code P0430. Installed 2 non-foulers on each post 02 and solved the issue for me.

Why pay $$$$ for a premium exhaust only to have a cheap fix? Seems like we’re getting junk lately from SS??

[LatinSkllz]

OP, are you running with a tune or still on the stock file?

[Cubieman]

I may try and put my post cat 02's back into commission just to see what happens with my HJS's.

[Tbonem3]

Why pay $$$$ for a premium exhaust only to have a cheap fix? Seems like we’re getting junk lately from SS??

HJS is not junk.

[Tbonem3]

EDIT: Came across an interesting thread on another forum where a Z4M owner had issued with his SS system due to EGT placement--more so power delivery and the ECU activating cat protection. Not sure if that's related here to this issue, but does raise the question: on our cars, EGT should be relocated to Section 1, or used in the header? SS apparently provides locations for both.

SS instructs to turn off EGT. As far as placement, the euro sect 1 with cats has the egt right before the cats - euro headers don't have egt so that should answer your question.