[intothelens4149]

I installed my DP/HFC 2 weeks ago. Week one no problems, week 2 popping cel's.
P0420 Catalyst System Efficiency Below Threshold (bank1)
I was monitoring the o2 sensor voltage with Torque app,
o2 Volts Bank 1 sensor 1, reads a steady 0.2 volts and never changes (closer.
02 Volts Bank 1 sensor 2, fluctuates between 0.5-0.8 but mostly 0.6-0.7.
at 70 mph under normal load.

When the cell comes on sensor 1 goes to zero and stays there until I clear the code then it goes back to 0.2 and never fluctuates.
Car runs fine, great power and great mpg.

Can some with the Torque app monitor the two o2 sensors and let me know what your readings are.

i welcome any input on this issue.

 

[intothelens4149]

^^^

 

[[email protected]]

throw a spark plug defouler in the post cat bung then thread the o2 sensor into that.. it's not uncommon for high flow cats to do this

 

[intothelens4149]

Thank you, I'll give it a shot. Just seems strange that for a whole week there were no issues and now it's daily cel's.

 

[MyDianaZ06]

I find it strange that Pierce Motorsports Down Pipe with high flow cat is actually throwing a code. This is a first and I bet if you told him this will be the first of him hearing his Down Pipe with high flow cat throw a code.

I was going to get his dp without a cat and just add 90 degree spacer at the bottom and be down with it.

From this post, I gathered people with a catless used a 90 degree spacer for the sensor past the cat and no spacers for the sensor before the cat and they haven't had any issues.

It is really weird that you have a cel come on with your high flow cat. I would just throw this on the sensor that is past the cat and I bet it would fix it.

whatever you do, please keep us updated for people in the future who go the same route and have the same problem

 

[intothelens4149]

I have been updating Jim, he is aware and I think I am the only one who has experienced this with the HFC.

 

[Frank2k21]

I have been updating Jim, he is aware and I think I am the only one who has experienced this with the HFC.

Nope, I got the code same time you did and let pierce know. I have HFC installed as well. I can't even reset it with my standard OBDII tester. : /

 

[lagonwagon]

intothelens, did you try a spacer yet?

 

[[email protected]]

I find it strange that Pierce Motorsports Down Pipe with high flow cat is actually throwing a code. This is a first and I bet if you told him this will be the first of him hearing his Down Pipe with high flow cat throw a code.

I was going to get his dp without a cat and just add 90 degree spacer at the bottom and be down with it.

From this post, I gathered people with a catless used a 90 degree spacer for the sensor past the cat and no spacers for the sensor before the cat and they haven't had any issues.

It is really weird that you have a cel come on with your high flow cat. I would just throw this on the sensor that is past the cat and I bet it would fix it.

whatever you do, please keep us updated for people in the future who go the same route and have the same problem

it's not uncommon at all for a HFC to throw a CEL on newer cars

 

[Frank2k21]

Well just drove a 50 min drive today (one way) the car had the CEL code the whole way there and all the way home. I stopped to grab some food, turned the car on and the CEL was gone....not sure what caused it to disappear.

 

[lagonwagon]

Not sure if it applies to the VT, but on a previous vehicle with a secondary o2 sensor issue it took three bad cycles to ping a code and the same number to clear it. Maybe the cat is walking a fine line between efficient enough and not.

 

[joebmoore4]

throw a spark plug defouler in the post cat bung then thread the o2 sensor into that.. it's not uncommon for high flow cats to do this

what size defouler would I need?

 

[GT800]

Its not quite that easy. You need 2 defowlers. 18mm ones. Then you need to drill out one thread it into the other then you can put your 02 into the drilled out one.

 

[GT800]

Also a lot of times with hfcs they flow to well at first until they get a bit of carbon buildup then they stop throwing codes.

 

[Darkhill240]

Are you talking about drilling out the defouler portion and and essentially are just extending the length of the defouler

 

[GT800]

Yup exactly. The o2 wont fit in just the one defouler you need the longer length of 2

 

[lagonwagon]

My dp popped this code after some dyno time. It cleared three days later on it's own. No defouler. I think that the repeated hard runs overheated the cat causing the efficience to drop enough to throw the code.

 

[joebmoore4]

Has any one had P0036- Powertrain - Fuel and Air Metering - ISO/SAE Controlled - HO2S heater Control Circuit (Bank 1 Sensor 2), pop up.....I have a gutted downpipe with a O2 extender on the rear O2 Sensor