Confusing Code Situation

[Good2Go]

Hello All,


2013 SHO Owner here, recently had my timing chain done. I have stainless works PPE downpipes / high flow cats with a Gearhead AO tune. My FIXD OBD2 scanner picks up stored P0420 & P0430 codes although they don't read on my dash. I tried to take my car in for inspection but it failed with the cats and o2 sensors stating "not ready" (I'm from NJ so I need at most one "not ready to pass"). Do you guys think its the tune causing that, or do you think its the drive cycle after the timing chain being done not being completed? I'm inclined to think it's the tune, I'm wondering if gearhead could fix it if it is?

 

[Joshw0000]

Hello All,


2013 SHO Owner here, recently had my timing chain done. I have stainless works PPE downpipes / high flow cats with a Gearhead AO tune. My FIXD OBD2 scanner picks up stored P0420 & P0430 codes although they don't read on my dash. I tried to take my car in for inspection but it failed with the cats and o2 sensors stating "not ready" (I'm from NJ so I need at most one "not ready to pass"). Do you guys think its the tune causing that, or do you think its the drive cycle after the timing chain being done not being completed? I'm inclined to think it's the tune, I'm wondering if gearhead could fix it if it is?

How many miles have you driven since the timing chain work? Worst case clear the codes, drive 50 or so miles, and check to see if they come back.

Sent from my Pixel 8 Pro using Tapatalk

 

[Good2Go]

How many miles have you driven since the timing chain work? Worst case clear the codes, drive 50 or so miles, and check to see if they come back.

Sent from my Pixel 8 Pro using Tapatalk

Over 1200 miles, I clear them and they always immediately pop back up even if I scan right after clearing them. Not sure if that tool clears stored codes but I’d imagine it would?

 

[Joshw0000]

Over 1200 miles, I clear them and they always immediately pop back up even if I scan right after clearing them. Not sure if that tool clears stored codes but I’d imagine it would?

When you say pop back up, you mean it returns "not ready"? They haven't actually failed and you have no CEL? Not ready just means, it hasn't passed the test yet (or failed).

Sent from my Pixel 8 Pro using Tapatalk

 

[Good2Go]

When you say pop back up, you mean it returns "not ready"? They haven't actually failed and you have no CEL? Not ready just means, it hasn't passed the test yet (or failed).

Sent from my Pixel 8 Pro using Tapatalk

Pop back up as in my own personal scanner immediately redisplays the codes after clearing them. I should add I also have an SCTX4, which does not pick up the codes (lending to the idea that they’re simply stored). The DMV’s OBD2 tool did not pick up any codes when I went for inspection, it simply read “not ready” for the cats and O2 sensors. The guy told me if codes were the issue they would’ve popped up there and it was most likely an issue with either my tune or the drive cycle, but I think after 1200 miles the drive cycle would’ve been completed

 

[Joshw0000]

Pop back up as in my own personal scanner immediately redisplays the codes after clearing them. I should add I also have an SCTX4, which does not pick up the codes (lending to the idea that they’re simply stored). The DMV’s OBD2 tool did not pick up any codes when I went for inspection, it simply read “not ready” for the cats and O2 sensors. The guy told me if codes were the issue they would’ve popped up there and it was most likely an issue with either my tune or the drive cycle, but I think after 1200 miles the drive cycle would’ve been completed

I'd say if you've driven more than 50 miles at multiple drive cycles (some city, some highway) after clearing codes and it still shows up on the scanner, then you most likely need to investigate the problem. Maybe start by seeing if a local shop can scan and give their feedback before you start replacing parts.

Sent from my Pixel 8 Pro using Tapatalk

 

[Good2Go]

I'd say if you've driven more than 50 miles at multiple drive cycles (some city, some highway) after clearing codes and it still shows up on the scanner, then you most likely need to investigate the problem. Maybe start by seeing if a local shop can scan and give their feedback before you start replacing parts.

Sent from my Pixel 8 Pro using Tapatalk

Alright, I’m gonna keep trying to get in touch with gearhead and see if they know anything about that. **** maybe I can just find a shop to give me a sticker anyway

 

[Joshw0000]

Alright, I’m gonna keep trying to get in touch with gearhead and see if they know anything about that. **** maybe I can just find a shop to give me a sticker anyway

My guess is your aftermarket cats. I've left my exhaust stock after the bad experience I had with my last car (S/C Mustang). I had x-pipes on it with high flow cats and ended up replacing them once, for the issue to return again. After that, I had them gutted and installed spark plug no foulers. My mechanic is pretty cool but he couldn't simply pass it until the codes showed ready.

Not sure about your state, but in mine, if I showed receipts of [X] amount (I forgot the amount), I could get an exemption for inspection. The problem is you have to do it every year until it's resolved.

Sent from my Pixel 8 Pro using Tapatalk

 

[Good2Go]

My guess is your aftermarket cats. I've left my exhaust stock after the bad experience I had with my last car (S/C Mustang). I had x-pipes on it with high flow cats and ended up replacing them once, for the issue to return again. After that, I had them gutted and installed spark plug no foulers. My mechanic is pretty cool but he couldn't simply pass it until the codes showed ready.

Not sure about your state, but in mine, if I showed receipts of [X] amount (I forgot the amount), I could get an exemption for inspection. The problem is you have to do it every year until it's resolved.

Sent from my Pixel 8 Pro using Tapatalk

Worst case scenario I still have the original cats and another set of O2 sensors so I could just go back to the originals and take the tune off

 

[Texas Marauder]

Permanent P0420 and P0430 cannot be cleared by a scan tool. Some scan tools will not display permanent codes. When the catalyst passes it's test the code will clear automatically. Permanent codes may or may not turn the CEL on.

Note that this is not the same as the OBD monitor showing "not ready". However, if the monitor should show "ready" the permanent code will probably go away. IOW, you can be "not ready" and have no permanent codes.

 

[Good2Go]

Permanent P0420 and P0430 cannot be cleared by a scan tool. Some scan tools will not display permanent codes. When the catalyst passes it's test the code will clear automatically. Permanent codes may or may not turn the CEL on.

Got it, that adds up with what I’m experiencing. I’ll see if my tuner can do anything about it. If not I’ll get the old cats back on and remove the tune just to get it inspected

 

[Tbird6]

My experience on another car is the "sports cats" usually are 200 cell and the factory ones are 400 cell. My tuner told me these would NOT meet emissions standards and the way past that was tuning out the O2 sensors monitoring the cat performance. BUT this also leads to the cat I/M monitor not setting ever.

This can be OK as depending on where you live most states don't require that all the I/M's be set at inspection time. Usually they allow one to have a "not ready" status.

After all that I also did what Joshw0000 did and just replaced it with a stock cat. No more codes and all monitors now set.
.
.
.

 

[Joshw0000]

I have no experience with them, but you may get a pass using something like this.

Mini Catalytic Converter Official | Mini Catalizador, O2 sensor spacer

Visit minicatalytic.com to explore the latest universal O2 sensor spacer, also known as the mini catalizador. This universal fit spacer features a built-in mini catalytic converter to enhance O2 sensor performance, reduce emissions, prevent check engine lights, and help pass emissions tests.

www.minicatalytic.com

Sent from my Pixel 8 Pro using Tapatalk

 

[Good2Go]

I have no experience with them, but you may get a pass using something like this.

Mini Catalytic Converter Official | Mini Catalizador, O2 sensor spacer

Visit minicatalytic.com to explore the latest universal O2 sensor spacer, also known as the mini catalizador. This universal fit spacer features a built-in mini catalytic converter to enhance O2 sensor performance, reduce emissions, prevent check engine lights, and help pass emissions tests.

www.minicatalytic.com

Sent from my Pixel 8 Pro using Tapatalk

Thanks for the recommendation. I think its my tune causing the I/M monitor not to set judging by these other replies and thus causing the problem so I don't think these would help since the code itself probably isnt the issue. But I could see how these could be super useful

 

[Good2Go]

My experience on another car is the "sports cats" usually are 200 cell and the factory ones are 400 cell. My tuner told me these would NOT meet emissions standards and the way past that was tuning out the O2 sensors monitoring the cat performance. BUT this also leads to the cat I/M monitor not setting ever.

This can be OK as depending on where you live most states don't require that all the I/M's be set at inspection time. Usually they allow one to have a "not ready" status.

After all that I also did what Joshw0000 did and just replaced it with a stock cat. No more codes and all monitors now set.
.
.
.

thanks. My issue is I have the cats and both o2 sensor categories set to "not ready". In NJ you're allowed to have one, but from what I'm reading from these replies my tune probably disables all 3. I'd like to make it clear that the car already had the tune when I bought it so I'm not super in touch with what exactly its doing as far as censoring these cat codes go.

 

[Joshw0000]

thanks. My issue is I have the cats and both o2 sensor categories set to "not ready". In NJ you're allowed to have one, but from what I'm reading from these replies my tune probably disables all 3. I'd like to make it clear that the car already had the tune when I bought it so I'm not super in touch with what exactly its doing as far as censoring these cat codes go.

Ah.... How long have you owned it? I was under the assumption all was fine before you had the work done.

Sent from my Pixel 8 Pro using Tapatalk

 

[Good2Go]

Ah.... How long have you owned it? I was under the assumption all was fine before you had the work done.

Sent from my Pixel 8 Pro using Tapatalk

About 2 years, tunes been on for almost the entire time. As far as the car running goes it runs great and pretty much always has aside from when I had to get the timing chain done, I just never had to have it inspected until now hence why I’m here. If it wasn’t for state inspection I wouldn’t care about this whatsoever

 

[Tbird6]

Just another comment? I have used the mini-cats and various spacers before and depending on how they are spaced into the cat they can and do work. Sometimes I have used straight or 90 degree versions and I have stacked them up too. I have had to mix and match until the car was happy. This took some time as cat efficiency codes require a certain amount of engine operation before they are set.

BUT what I have found is if the cat is throwing efficiency codes you have a good chance the cat will get worse. What I mean by that is what happened to me. I finally got that dang cat efficiency code to go out and passed my inspection. Car drove fine and I had no codes...for a while.

A couple of months went by and I started getting the code again. Well the brick inside the cat had started to collapse and actually plugged the hole where the O2 sensor and the spacers were installed. So now the O2 sensor was getting zero exhaust flow so of course it started throwing codes!

You can see the white of the catalytic brick completely blocking the O2 port.



I have read where it gets so bad chunks of the cat started going out the exhaust and get caught in the mufflers. Giving you some nice rattles!

Oh and don't forget the spark plug Non-Foulers too. I was surprised but the same thread is used on O2 sensors and spark plugs. About $8 at any parts store.
.
.
.

 

[Good2Go]

Just another comment? I have used the mini-cats and various spacers before and depending on how they are spaced into the cat they can and do work. Sometimes I have used straight or 90 degree versions and I have stacked them up too. I have had to mix and match until the car was happy. This took some time as cat efficiency codes require a certain amount of engine operation before they are set.

BUT what I have found is if the cat is throwing efficiency codes you have a good chance the cat will get worse. What I mean by that is what happened to me. I finally got that dang cat efficiency code to go out and passed my inspection. Car drove fine and I had no codes...for a while.

A couple of months went by and I started getting the code again. Well the brick inside the cat had started to collapse and actually plugged the hole where the O2 sensor and the spacers were installed. So now the O2 sensor was getting zero exhaust flow so of course it started throwing codes!

You can see the white of the catalytic brick completely blocking the O2 port.

View attachment 94583

I have read where it gets so bad chunks of the cat started going out the exhaust and get caught in the mufflers. Giving you some nice rattles!

Oh and don't forget the spark plug Non-Foulers too. I was surprised but the same thread is used on O2 sensors and spark plugs. About $8 at any parts store.
.
.
.

Yeah I may consider just going back to the stock cats / tune soon. I was already considering going back to them in the fall / winter but I might just do it within the coming month so I can pass inspection and get a tiny bit extra MPG, at the end of the day I'm not racing anyone with this thing so while I'll miss the extra power not sure if I'll really need it