So I’m throwing a p0420 is saying Catalyst System efficiency below threshold bank 1

My tuner won’t tune the code out because they say it’s illegal and I won’t pass emissions with it disabled. I thought it would be the opposite? If HFC isn’t up to par” I’d still fail but would also fail if it’s disabled? What are my options to get rid of this consistent code? I also don’t even have emission testing in my county. And my HFC is by MAP

 

Can you disable the code and force the monitor to pass? Can't you just put an O2 spacer on this and push it out of the flow? Why did you not get a straight pipe instead?

 

Where I’m living isn’t permanent so I thought I’d go HFC incase I do need emissions one day. So even though my tuner won’t do it for me. I can get use a program to disable the code myself? And if I did this I wouldn’t need the spacer then right?

also I just got an ECU tune so if I did disable the code would it mess with anything to do with the tune they did?

 

You should have just kept your original CAT in storage, and installed a straight pipe. This way you can go back if you needed to.

Disabling codes and forcing monitors will not affect the driving portion of your tune. You should be researching openECU. This is what I used on my IX- along with the force readiness tricks..

The spacer trick is simple and effective. Switch ratio checks are easy to beat.

 

so I have two options. Tune it out or try the spacer and leave the tune alone?

 

Don't think of it as "tuning it out". Think of it as "turning it off".

"Tuning" is the process of slowly adjusting the fuel injection pulse and the ignition timing to deliver the best results. There are other things like Mivec advance- but here you are "dialing in" something to perfection.

If the X works with index switch ratio (which I bet it does, like my IX did) than the spacer trick is the easy way to go. I still think it was foolish to buy a HFC in the first place. I would have straight piped it.

 

i understand where you’re coming from but a HFC would pass emissions vs a test pipe failing correct? So if I ended up living in an Emission testing zone I would have to swap parts for emission every time. Not something I want to do. Either way I appreciate your advice so thank you.

 

It all depends if you have an EPA **** test like some states have, or not. Some states just check electronically. Some states will only allow factory CATs or those that meet those certifications.

 

So my state doesn’t do visual inspections I believe they only do a plug into OBD2 port. But either way I don’t have to deal with emission testing. So you think spacer would be the easiest? I have no experience with tuning programs so idk how difficult it would be to just turn off the code.

 

If you have no experience with tactrix/changing parameters with software. You should go the spacer route, though they are hard to find now on amazon and ebay.

 

You don't need a specialized part from ebay or amazon. Go to your local parts store- Autozone, Advanced Auto, O-Reily's. Pick up a spark plug defouler package. It should be a few dollars. I believe the part number is "HELP 42009" or something very similar to that. Put this between the cat and the rear O2. (don't forget to anti-seize the threads) Done.

 

I'm surprised autozone still sells them after all that EPA regulation stuff. That's why amazon and ebay stopped selling the "spacer" which is the same thing.

 

These are spark plug defoulers... they have the exact same thread as an oxygen sensor and serve the exact same thing, but they are not MARKETED directly for making your car pass emissions. These were around years, years, years before it was known that it would reduce switch-rate on a narrow-band o2 sensor.

The EPA may as well make it illegal to buy metal because this can be used to pass emissions... What are they going to do- make welders illegal also?

 

What cat did you purchase? What is the cell count?

It seems that others have had success so I am curious what is unique about your setup.

 

If they had their way, I bet they would...