CAT Monitor test won’t turn on in VCDS

[b6_nikola]

Been having an issue the last few months with the cat monitor not setting ready. I bought a hex cable & downloaded vcds. deleted any codes that were stored & then ran readiness tests for all the monitors. all ready except cat monitor. when i go to block 46 to run the test, it wont even turn it on/run it. any tips??


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[imnuts]

Is your car tuned? If so, what tuning do you have?

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[MetalMan]

Were any of the stored codes related to oxygen sensors? And if you drive the car for an extended period (at least 50 miles), do any codes return?

[EuroxS4]

In order to run all emissions test you need to do these in the order listed here. Hope this helps.

readiness.png


Catalyst test needs a temp of 550 degrees C to start running the test. Please follow the chart and report back.

[b6_nikola]

Is your car tuned? If so, what tuning do you have?

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yes it is tuned. it’s an older Revo stage 2 tune. previous owner has ran it for about 10 years with no issues at all


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[b6_nikola]

In order to run all emissions test you need to do these in the order listed here. Hope this helps.

readiness.png


Catalyst test needs a temp of 550 degrees C to start running the test. Please follow the chart and report back.

ive done it multiple times over the last few months. the cat monitor test wont run. channel 3 stays at 0 & does not change value. im gonna change the o2 sensors when i get back home & see if that changes anything


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[ReinS]

Hi,
If I remember correctly, then you have to run 034 and 036 at first. Only after that 046 activates. And as EuroxS4 said temp is important.

[EuroxS4]

Hi,
If I remember correctly, then you have to run 034 and 036 at first. Only after that 046 activates. And as EuroxS4 said temp is important.

Yes they have to be done in that order as mentioned. However Field 3 staying at 0 would indicate an issue. If the vehicle throwing any faults at this time for o2 sensors or anything?? IIRC Field 3 usually shows flow in g/s to determine flow and then determines wether the cat is good or not. Does MVB 036 show b1-s2 ok in field 2 when running that test?? If rear o2 sensor is coded out It will never set readiness for catalyst.

[b6_nikola]

Yes they have to be done in that order as mentioned. However Field 3 staying at 0 would indicate an issue. If the vehicle throwing any faults at this time for o2 sensors or anything?? IIRC Field 3 usually shows flow in g/s to determine flow and then determines wether the cat is good or not. Does MVB 036 show b1-s2 ok in field 2 when running that test?? If rear o2 sensor is coded out It will never set readiness for catalyst.

no codes for o2 sensors. yes b1-s1 ok & b1-s2 ok. ran thru tests multiple times. im gonna change o2 sensors see if that changes anything if not gonna have to swap injectors & flash it back to stock & see if that helps. previous owner who had it tuned is on audizine & ive been in contact with him & he doesnt think rear o2 was disabled since he always passed emissions. but since it is an older tune (10yrs old) theres a possibility it was.


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[imnuts]

Most places will allow you to pass with one readiness monitor not set. I'm not sure how REVO did their tune, so I can't say for certain that is the case, but it is a possibility.

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[b6_nikola]

Most places will allow you to pass with one readiness monitor not set. I'm not sure how REVO did their tune, so I can't say for certain that is the case, but it is a possibility.

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unfortunately cat monitor has to be ready for me to pass :( & i dont have anyone local that wants to look at the tune. audi dealership wont touch it since it’s tuned. i bought some used oem injectors just incase i need to go back to stock to pass emissions


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[frogspit]

revo stage 2 disables that test, you need to flash back to stock. iirc the revo stage 1 tune doesnt code out the test either, but 2 and above does


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[Gin+]

revo stage 2 disables that test, you need to flash back to stock. iirc the revo stage 1 tune doesnt code out the test either, but 2 and above does


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A quick google supports this theory.

[EuroxS4]

Most places will allow you to pass with one readiness monitor not set. I'm not sure how REVO did their tune, so I can't say for certain that is the case, but it is a possibility.

Sent from my Pixel 5

Yes they will let you pas with one monitor not set however that monitor cannot be emissions related. Flash back to stock and set readiness if no cat need to modify CDKAT map in ecu.

[b6_nikola]

Yes they will let you pas with one monitor not set however that monitor cannot be emissions related. Flash back to stock and set readiness if no cat need to modify CDKAT map in ecu.

yup exactly & now the hazards wont stop blinking. i swear every time i leave town some bs happens


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