Ryan’s ‘23 A91MT Burnout - Slow Build

[razorlab]

That’s what I wanted to see, what the CIDs and CVN look like before and after unlock without MHD.

Flashing back to stock map with MHD installed, your CVN will still change and not match OEM spec. But supposedly if you’re relocked or flashed by the dealer it should revert to OEM spec, even with the permanent unlock.

I'll have someone else test that. I have no interest in flashing back to stock.

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[Razors Edge]

Confirmed today that CVN does indeed change with MHD.

This is my M240i before and after flashing it with MHD.

This means those of us in Commiefornia and similar shit hole cess pool political states are screwed, unless you want to dealer level flash (and pay probably a very large bill to do it) back to stock every 2 years.

 

[RyanA90]

Just ordered this is convert my BMS Flex Fuel into canbus (ECA). Goal is for a custom flex fuel tune: https://burgertuning.com/products/b...eH3iTqtf4b7bSQJS89CeMn&variant=45995176919214

 

[RyanA90]

CEL kept popping up and it looks like I gotta replace the downstream o2 sensor! I found it on sale here if anyone needs one about $145 shipped: https://autoparts.springhilltoyota....01077_google_dsplus_shopping_SpringhillToyota

 

[Eastwood]

CEL kept popping up and it looks like I gotta replace the downstream o2 sensor! I found it on sale here if anyone needs one about $145 shipped: https://autoparts.springhilltoyota....01077_google_dsplus_shopping_SpringhillToyota

Are you catless or catted downpipe?

 

[RyanA90]

Are you catless or catted downpipe?

Catless

 

[Eastwood]

Catless

Oh I checked first post, you have the FI Downpipe? You sure it's not the downpipe causing the CEL?

 

[RyanA90]

Oh I checked first post, you have the FI Downpipe? You sure it's not the downpipe causing the CEL?

Yeah. Its a catless with a built in defouler which shouldn't throw a code.

 

[Eastwood]

Yeah. Its a catless with a built in defouler which shouldn't throw a code.

It shouldn’t, but sometimes it does lol. Ask a local buddy if you can swap O2 sensors real quick just to see.

Had that happen to me on a previous car, I was able to return the sensor at least.

 

[i3igpete]

I think i have a theory that this is indirectly caused by cold start noise reduction on catless DPs. With oem cold start, the o2 sensor warmup is "close enough". With cold start noise reduction, the DME thinks "huh, it shouldnt be this hot already, i didnt send enough flow thru yet". The cat, while normally an exothermic reaction at operating temp, requires a lot of heat to kickstart the reactions and thus acts like a heat sink at first.

Can you try turning cold start noise reduction OFF but leave downpipe set to STOCK and see if the codes come back?

 

[RyanA90]

I think i have a theory that this is indirectly caused by cold start noise reduction on catless DPs. With oem cold start, the o2 sensor warmup is "close enough". With cold start noise reduction, the DME thinks "huh, it shouldnt be this hot already, i didnt send enough flow thru yet". The cat, while normally an exothermic reaction at operating temp, requires a lot of heat to kickstart the reactions and thus acts like a heat sink at first.

Can you try turning cold start noise reduction OFF but leave downpipe set to STOCK and see if the codes come back?

Ok I'll try this

 

[razorlab]

I think i have a theory that this is indirectly caused by cold start noise reduction on catless DPs. With oem cold start, the o2 sensor warmup is "close enough". With cold start noise reduction, the DME thinks "huh, it shouldnt be this hot already, i didnt send enough flow thru yet". The cat, while normally an exothermic reaction at operating temp, requires a lot of heat to kickstart the reactions and thus acts like a heat sink at first.

Can you try turning cold start noise reduction OFF but leave downpipe set to STOCK and see if the codes come back?

I have cold start turned off and have yet to get any codes from it.

It might be the bung spacing in the DP. What does the rear 02 bung look like on this DP?

 

[RyanA90]

I have cold start turned off and have yet to get any codes from it.

It might be the bung spacing in the DP. What does the rear 02 bung look like on this DP?

 

[ColonelAdama]

I think i have a theory that this is indirectly caused by cold start noise reduction on catless DPs. With oem cold start, the o2 sensor warmup is "close enough". With cold start noise reduction, the DME thinks "huh, it shouldnt be this hot already, i didnt send enough flow thru yet". The cat, while normally an exothermic reaction at operating temp, requires a lot of heat to kickstart the reactions and thus acts like a heat sink at first.

Can you try turning cold start noise reduction OFF but leave downpipe set to STOCK and see if the codes come back?

I also have cold start off and have gotten this code recently with my kenji catless that never gave me a CEL while locked. Probably same issue.

 

[i3igpete]

Yeah, same here. Never a problem with my armytrix for 25k miles while locked, got unlocked and within the first 500 miles it threw the code. I can't turn off catalyst monitoring since that is the one system that cant show as "not available" to pass emissions.

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