catted headers + OFT = automatic smog fail?

[DarkSideFRS]

Just curious if this is the case. Looking to free up a bit more power with catted headers and the OFT tune, but keeping everything else stock. Will it fail smog?

Option 2 is to remove the OEM cat and weld a hi-flow cat in its place. Do I need a tune if I do that? I would think this option would have a higher chance of passing smog since no tuning is required?

[Thaeyo]

You'll need a tune to gain any real value from going UEL/EL header. Even with catted you'll throw the occasional CEL. It's too early for anyone to test for Smog due to 6 year rule.

[TofuJoe]

A catted header will fail the visual on a smog test.

I had the JDL catted header, and if I was doing it over again, I'd go catless. Catted makes less power. The upside of catted is that it's quieter.

I'd also recommend an ECUTek tune instead of an OFT tune if you're going catted. The OFT isn't optimized for catted headers.

For Option 2 you won't fail the visual. A tune would be optimal. You might also search for people who've gutted the catted header and not welded anything back in.

[Decimus]

Just swap it out when it comes time. Header swap is so easy. Go catless header for better gains. Oft will get you through the torque curve and youll free up 20+ hp.

[DarkSideFRS]

i ran a gutted cat in my honda and i can't stand the smell haha.. tht's why i prefer a catted

i have seen ppl gutting the cat in the frs, but they tune it afterwards to maximize power... is it possible to gut the cat or replace with hi-flow cat and not tune it? just curious what the gains would be

as for passing smog, i thought any adjustment done to the ecu is considered a failed smog? i heard of OFT as being difficult to detect?

[guybo]

To revert to the stock tune takes 5 minutes with OFT. The header takes a couple hours to install. Changes in the header/exhaust/intake etc create minimal power increases because the stock tune will limit the engine to an increase of about 5% total. The engine management is very conservative like that so you need a tune to really wake the car up.

Buy a used stock header and gut it. Install (passes visual test and the stock heat shield protects the engine components from heat) and tune on Stage 2 with OFT. The car will feel like it has a new engine. when it's time for the smog test, reinstall your orig header (a few hundred miles in advance so you don't get dinged with readiness tests) and reinstall orig tune. profit


You can go Stage 1 OFT with the stock header; an aftermarket catted header + Stage 1 OFT are not really worth the minimal gains for the cost IMHO. In fact, stage 1 OFT has minimal gains with any header. The P0420 is not turned off with the Stage 1 tune, so that should pass a smog test easy. But like I said- it's 5 minutes to revert to the stock tune so the point is moot anyway

[DarkSideFRS]

Originally Posted by guybo

To revert to the stock tune takes 5 minutes with OFT. The header takes a couple hours to install. Changes in the header/exhaust/intake etc create minimal power increases because the stock tune will limit the engine to an increase of about 5% total. The engine management is very conservative like that so you need a tune to really wake the car up.

Buy a used stock header and gut it. Install (passes visual test and the stock heat shield protects the engine components from heat) and tune on Stage 2 with OFT. The car will feel like it has a new engine. when it's time for the smog test, reinstall your orig header (a few hundred miles in advance so you don't get dinged with readiness tests) and reinstall orig tune. profit


You can go Stage 1 OFT with the stock header; an aftermarket catted header + Stage 1 OFT are not really worth the minimal gains for the cost IMHO. In fact, stage 1 OFT has minimal gains with any header. The P0420 is not turned off with the Stage 1 tune, so that should pass a smog test easy. But like I said- it's 5 minutes to revert to the stock tune so the point is moot anyway

thanks for the info. This was very helpful. Didn't know i could run a stage 2 tune with just a gutted cat.

altho the OFT tune can be reverted easily to stock tune, could the smog station detect that u messed with the ECU and fail u for tht? I believe the smog test for newer cars do not include the sniff test? it's just visual test and ecu test from what I remember

[guybo]

You'll fail, but not because they can detect an aftermarket tune- there's nothing illegal in that per se. But a stage 2 tune disables the P0420 CEL and that is detectable. Your car will fail for the OBD Monitor Not Ready. Stage 1 does not disable the P0420 CEL and you'll pass inspection- from what I understand. FL has no state inspection so I have no personal experience there.

If you flash your tune then drive right away to the inspection station, you'll most likely fail too because it takes a certain number of miles and drive cycles to run those tests. That's why when you decat (or clear the P0420 code) then drive, the P0420 takes a good 50-100 miles to come on.