B8 A4 DIY: Catalytic Converter Removal & HFC or Test Pipe Install

[boomtime]

Thanks man.


On another note does anyone here in ontario have any problems with hfcs and emissions? Another question i cant find an answer to

You shouldnt if you use the 90* spacer on the rear O2...so it wont set the CEL (telling them to replace your cat).
And since its permanent AWD they should not put it on the rollers...not sure if they do that up there or not either way.
We dont have inspection in Florida.

[Marko S]

So i purchased an 034 hfc from eurosporttuning in oakville and they were awesome. Im getting it installed sometime this week but have a question about the spacer. There are 3 different jets (on the top of the picture). Which one of these should I use? I've read 90* is best but dont know which is which.

I posted this question in another but got no response so I am posting here as I'd like to install this today. Thanks!

[bermudakid]

^ The smaller inserts are there to let you pick how much flow you want to get to the secondary 02 sensor. Pick one, if it works leave it if you still get a code go smaller.



Also you install this to the sensor on the HFC why would you install it today if you are getting the HFC installed later in the week??

[Marko S]

^ The smaller inserts are there to let you pick how much flow you want to get to the secondary 02 sensor. Pick one, if it works leave it if you still get a code go smaller.



Also you install this to the sensor on the HFC why would you install it today if you are getting the HFC installed later in the week??

I didnt want to get a code but i guess ill try the middle one. And sorry initially was going to get it installes next week but some time opened up today so going to do it today

[Fox Fader]

Here's the one I've been using for months with no ill effects at all. Got it on ebay, like $12.

[SWONER]

This is what happens when you try to tackle this mod alone...

Sent from my SM-G925V using Tapatalk

[boomtime]

This is what happens when you try to tackle this mod alone... https://images.tapatalk-cdn.com/15/06...d16aaa0358.jpg

Sent from my SM-G925V using Tapatalk

Poor cat from South Africa... Mine is going back on so I would never have cut it!

[richardm0025]

This is what happens when you try to tackle this mod alone...

Sent from my SM-G925V using Tapatalk

Lol, you should have had a beer or two and have been more patient!


Sent from my iPhone using Tapatalk

[trackbaron]

Looks like you took a wrong turn somewhere mate lol

[blbroo]

This is what happens when you try to tackle this mod alone...

Sent from my SM-G925V using Tapatalk

Maybe you should start your own HFC DIY. The "f#@& it" method.

[TommyK]

Damn i wouldn't think that was possible to shatter the metal like that

[blbroo]

Damn i wouldn't think that was possible to shatter the metal like that

Sure it will, when you hit it with one of these...

[Fox Fader]

Wow! Didn't think I'd ever see that.

[bermudakid]

This is what happens when you try to tackle this mod alone...

Sent from my SM-G925V using Tapatalk

Lmao.

Nice work! This is exactly how I imagined i would've done it on my own.

[Fburg A4]

wow, that is one way to do it! i applaud the creativity

[Smellie]

"Selling OEM Cat, Like new"

[richardm0025]

"Selling OEM Cat, Like new"

Lmao


Sent from my iPhone using Tapatalk

[boomtime]

"Selling OEM Cat, Like new"

JB WELD should hold that together no problem!

[Marko S]

Hey guys,

Got the 034 hfc installed and popped a CEL with the middle orifice. Going to get some help with it in the next couple of days, but in the mean time am I ok to drive with it?

[Fox Fader]

Hey guys,

Got the 034 hfc installed and popped a CEL with the middle orifice. Going to get some help with it in the next couple of days, but in the mean time am I ok to drive with it?

What's the middle orifice? If you'd just said you got a CEL, I'd say, yes, you can drive it safely.

[Marko S]

What's the middle orifice? If you'd just said you got a CEL, I'd say, yes, you can drive it safely.

Thankss. Umm there are 3 different sized jets (also called orifices) that can be inserted into the 02 extension.

[diego_demarco]

Contemplating getting an Hfc again to add to my awe dp and quad exhaust but not sure I feel like dealing with Cel's every other week :/

[KFizz]

Has anyone installed a testpipe and downpipe with the stock exhaust? I just finished installing a CTS testpipe with downpipe. I'm really surprised at how loud it is. I was expecting it to be louder than stock, but this is obnoxious. It sounds like a straight piped STI or something.

The fitment of the DP wasn't great. I had to do some trimming on one of the straight sections to get it to fit. Is it normal for this to be such a loud setup??

Sent from my Nexus 5 using Tapatalk

[Marko S]

So I ran a test and got this code:

10434 - Catalyst System; Bank 1
P0420 00 [237] - Efficiency Below Threshold
MIL ON - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 4
Mileage: 63616 km
Date: 2015.06.24
Time: 19:03:24

Does this mean that there is not enough air flow going to the O2 sensor?

Also got these 2 faults:

4057 - Cylinder 2
P0302 00 [096] - Misfire Detected
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 63574 km
Date: 2015.06.23
Time: 11:52:07

4051 - Random/Multiple Cylinder Misfire Detected
P0300 00 [096] - -
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 63574 km
Date: 2015.06.23
Time: 11:51:31

I feel like this is due to the coils/spark plugs but could it be related to the hfc?

[boomtime]

It means the spacer isnt working,
The misfires are something else.

[Marko S]

It means the spacer isnt working,
The misfires are something else.

Thanks...
Do you think the misfires are due to the coils/spark plugs?

[boomtime]

Thanks...
Do you think the misfires are due to the coils/spark plugs?

It depends, you should clear the codes and then see if they come back right away or maybe after a certain driving condition.
From my experience its usually crappy gas.

[kskevin]

This thread was SOOOOO helpful. Couldn't have done the install without it. Got my HFC delivered Wednesday evening and did the install Thursday evening, flashed Friday to APR Stg 2 (e85). No helper for the install and was still able to complete in 3.5hrs. Thanks for the tutorial guys.

[oshwi]

So i just did this 10 mins ago, needless to say i sheared 2 bolts from the cat to midpipe. Should i be ok with just 1 bolt in the middle holding the thing? Im hearing a little drone. Is that normal? And yea, this thing is a freakin pain in the ass! Lol

[blbroo]

So i just did this 10 mins ago, needless to say i sheared 2 bolts from the cat to midpipe. Should i be ok with just 1 bolt in the middle holding the thing? Im hearing a little drone. Is that normal? And yea, this thing is a freakin pain in the ass! Lol

I wouldn't do that. Most of us that have the same issue drill the stud out and use generic hardware to hold it together.

[adamazing]

If anyone in Cali with an HFC is coming due for smog, please post up your experience.

Cali (finally) crossed over to the OBD diagnostic and replaced the actual measurement testing (which was supposed to be done two years ago). This means no more sniff testing. BUT there is still a detailed visual inspection. Since most HFC's have a strong third party look to them, I'd like to hear personal experiences and Smog testing success rates with them.

[Lambda13]

If anyone in Cali with an HFC is coming due for smog, please post up your experience.

Cali (finally) crossed over to the OBD diagnostic and replaced the actual measurement testing (which was supposed to be done two years ago). This means no more sniff testing. BUT there is still a detailed visual inspection. Since most HFC's have a strong third party look to them, I'd like to hear personal experiences and Smog testing success rates with them.

Could you paint it to make it look normal?

[blbroo]

Could you paint it to make it look normal?

Are you drunk Andrew? After a while, they change color to that brown / copperish tone that the stock one has when you take it off. I am not sure they would notice my HFC but the spaced out O2 sensor is obvious. Luckily, the guy that just installed my muffler mentioned that he doesn't go looking for trouble if the ODB2 scans ok on inspections.

[oshwi]

Hey blbroo, how hard was it to drill out? What equipment did you use? And did you take the midpipe out to do it? Thanks! Sorry for all the questions

[blbroo]

Hey blbroo, how hard was it to drill out? What equipment did you use? And did you take the midpipe out to do it? Thanks! Sorry for all the questions

I had the midpipe (downpipe) out anyway per the instructions I used. I just used a drill and a strong bit, didn't take much effort. The pipe is easy to get out once you have it disconnected from the cat, the other end is just in a slip joint.

[oshwi]

The nut and bolts on the slip joint is also corroded. I guess all the salt in nj just killed it. What a bother, dang.

[trackbaron]

Replace them and drive with peace of mind...

Sent from my SM-N900V using Tapatalk

[adamazing]

Could you paint it to make it look normal?

If it were to be an issue, I was thinking more along the lines of heat wrapping it.

[oshwi]

After some heating and a bunch of cussing, i finally got that stud from the mid pipe to cat removed. Thanks guys!

[Shaph]

One note for RHD models

You must remove the oxygen sensors in order to remove the cat.
It can only be removed from the top as the steering wheel column does not allow removal from underneath.
Use a tool pull to the cat from above such as a narrow pole and slowly pry forward.