Downpipe CEL solution?

[Bassoonytoon]

Hi all,

I have been considering getting a downpipe and a JB+. I have an untuneable 2021 which is fine as I’m not interested in a tune right now, but I am curious about clearing a CEL that a downpipe may cause.

As I understand it, Bimmerlink won’t clear any codes to do with emissions. However, the OBDLink app (which seems to be a branded version of OBD Fusion) has a “Diagnostics” section which allows users to clear codes. On other forums, I have read that OBD Fusion allows emissions codes to be cleared.

So here’s my question:

Given that a lot of people on this forum would have an OBDLink and thus have access to their app, does anyone know if the OBDLink app will allow codes thrown from a downpipe install to be cleared. If so, will the codes come back after a while?

Thanks in advance!

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[zrk]

You can clear it with JB4. It'll come back, then you clear it again.

 

[Vroomin350]

@zrk you think it’s a bad idea to run a catted DP/intake without jb4?… I have an active catted dp but haven’t installed due to not having jb4, wondering if it’s ok or I should wait

 

[romanLegion9574]

@zrk you think it’s a bad idea to run a catted DP/intake without jb4?… I have an active catted dp but haven’t installed due to not having jb4, wondering if it’s ok or I should wait

You can: https://www.supramkv.com/threads/intake-and-catless-downpipe-without-tune.9734/

 

[Jesse DaBears]

Like @zrk said you can clear the code just cant disable it with the JB4. I have both in stock and can do a package deal for ya

www.1fastsupra.com

 

[Bassoonytoon]

Thanks for the replies so far. I appreciate the feedback. To be clear though, I am looking at a JB+, not a JB4 - this is why I’m curious if it’s possible to clear the code with an app.

I suspect if JB4 can clear code it may be possible with the OBDLink app/OBD Fusion. How long does it take for the CEL to pop back up with the JB4?

 

[Mimosa]

I've had the Armytrix catless DP w/ simulator for months and haven't had a CEL. This is with no tune at all.

 

[Killswitch24]

Buy a Active Autowerke catted dp and you won't have this issue. Or, do like @Mimosa and go catless with a spacer/simulator. You won't want to bother with clearing the CEL every time it pops on.

 

[AHP]

I have the AMS catted dp -- no CEL, no raw exhaust smell and I'm running as fast as catless cars with the same mods.

 

[MisterSkiz]

I've had the Armytrix catless DP w/ simulator for months and haven't had a CEL. This is with no tune at all.

Do you have a link to the simulator? Supposedly they don't work well in this car - would be interesting to see which one you are using

 

[Jesse DaBears]

Thanks for the replies so far. I appreciate the feedback. To be clear though, I am looking at a JB+, not a JB4 - this is why I’m curious if it’s possible to clear the code with an app.

I suspect if JB4 can clear code it may be possible with the OBDLink app/OBD Fusion. How long does it take for the CEL to pop back up with the JB4?

why a jb+ that has zero customization and no better than a racechip.

 

[Bassoonytoon]

why a jb+ that has zero customization and no better than a racechip.

Fair question - I just want something simple.
If the JB+ is reliable and can give me 15-25 horsepower then I’m happy. Pretty decent for <$250 USD.

The downpipe would basically be for a little more sound and possibly better flow/slightly more power.

As I understand it, the JB+ will give more power in the higher RPM range, but a better flowing downpipe can improve power in the low-end range. I figured this combination give me a little of both.

I don’t want to go too far down the tuning rabbit hole. I get that I’m not going to be making 450whp but that’s not the goal - if i can get around 400whp that would be great for me (I believe the ‘21’s dyno around 380 stock).

I’m still not sure about my original question - can an app clear the CEL a downpipe may cause? If it only clears it temporary, how long before it comes back?

Thanks again all for the feedback so far.

 

[Jesse DaBears]

Fair question - I just want something simple.
If the JB+ is reliable and can give me 15-25 horsepower then I’m happy. Pretty decent for <$250 USD.

The downpipe would basically be for a little more sound and possibly better flow/slightly more power.

As I understand it, the JB+ will give more power in the higher RPM range, but a better flowing downpipe can improve power in the low-end range. I figured this combination give me a little of both.

I don’t want to go too far down the tuning rabbit hole. I get that I’m not going to be making 450whp but that’s not the goal - if i can get around 400whp that would be great for me (I believe the ‘21’s dyno around 380 stock).

I’m still not sure about my original question - can an app clear the CEL a downpipe may cause? If it only clears it temporary, how long before it comes back?

Thanks again all for the feedback so far.

But what do you do with the JB+ if you are over boosting or overshooting boost targets from a catless downpipe?

IMO tuning solutions is never something you should cheap out on. Its $678 + shipping for a JB4 but it can save you tons of headaches and $ if you have an issue.

 

[Bassoonytoon]

But what do you do with the JB+ if you are over boosting or overshooting boost targets from a catless downpipe?

IMO tuning solutions is never something you should cheap out on. Its $678 + shipping for a JB4 but it can save you tons of headaches and $ if you have an issue.

Again this is a fair point but I wasn't trying to cheap out on it, just trying to stay simple. I would rather stay stock than get too far into tuning. I thought JB+ was a reliable option but maybe I should reconsider.

Also to be clear, I was looking at a catted downpipe, but according to a poll here that doesn't mean I will be avoiding a CEL: Have you gotten a CEL with your "No CEL guarantee" catted downpipes? (no tune!) | SupraMKV - 2020+ Toyota Supra Forum (A90 MKV Generation)

So, is the JB+ a product that I should avoid?

 

[MisterSkiz]

The JB+ is fine (I have one and turned up the gain on it) , but it wont get you logging, more power, etc like the full blown JB4 unit will.

I bought one because it was something to tide me over until I could get a full tuning solution.

In regards your original question - I have used used ODB Fusion and Torque to clear emission codes on other cars with no issues, but not the Supra.

When will the code come back? Probably in a couple of days.

The other problem you will have is passing emissions testing if you have them in your province. When you clear the code, it puts your emissions tests in the ECU back in "not ready / learn mode" until you pass a certain amount of time driving, RPM changes, etc. During this time you will not be able to pass emissions.

What will happen when you meet all the requirements to pass the test in your ECU, is that it will set a check engine light and you are right back at square one.

If you want a catless downpipe on any car, you have two choices 1) A computer tune that removes the rear 02 sensor checks, or 2) some type of simulators/extenders that either modify voltage from the rear 02 sensors or extends the rear 02 sensors away from the downpipe.

On newer cars the simulators do not work that well, if at all. Your true solution is a full computer tune that deletes these rear 02 codes.

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