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

[richardm0025]

Well after a few beers in me, I thought this was the best idea to do it since I was by my self haha. I just stood in the engine bay and put a rope under that wrench and pulled up and that "PIA" nut came right off. I sure felt lucky, doing it this way took about 9 minutes total to get all 4 nuts off on the top end. I just took a grinder and cut the other end of the wrench off so it could fit underneath.

[Jerry1847]

Here's an update for you. I started the car up this morning to head to work and no CEL.

you still without CEL? I got one after ~45min. I clear it and it just comes back...

[Jerry1847]

The two times I have done this install, I was able to get around to the back bolt with a straight extension and use the space behind the engine to get it off. I reached under the cat and was able to guide the socket on with fingertips. I think I used a breaker pipe to initially pop the bolt loose without breaking my hand. Also, both times it took me probably 30 minutes of trying to get the cat out of the bottom instead of the top. The second time was just embarrasing once I realized what I did.

I have the angled roceuro spacer with the catalyst in it, and got a code on my first trip out of the neighborhood. I have since backed the spacer out a bit, so we will see if the CEL comes back once I get it cleared.

Did the same thing, deep 15mm on a ~10 or 15 in extension. Got the socket (w/ extension) on by hand then slowly attached a pivot and wrench with another extension on it. Came off with little force.

[Frinkferta]

Well after a few beers in me, I thought this was the best idea to do it since I was by my self haha. I just stood in the engine bay and put a rope under that wrench and pulled up and that "PIA" nut came right off. I sure felt lucky, doing it this way took about 9 minutes total to get all 4 nuts off on the top end. I just took a grinder and cut the other end of the wrench off so it could fit underneath.

Haha! Use PB blaster! It will loosen those nuts and makes the process WAY easier! A standard wrench and socket did it for me.


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[richardm0025]

That's exactly what I did haha yeah this is a great little DIY project!


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[simek3ru]

you still without CEL? I got one after ~45min. I clear it and it just comes back...

Yup, still without a CEL. About 200 miles so far. What spacer are you using?

[richardm0025]

Loving my new HFC. I actually feel like its a whole different car, no CEL but only driven it 15 miles. Def a lot of smoke from it braking in and maybe PB blaster haha?!

[Jerry1847]

Yup, still without a CEL. About 200 miles so far. What spacer are you using?

Argh! No spacer.
The stage 2 tune will eliminate the CEL right?
I started keeping an old netbook with the vagcom software in my car along with a set of emergency repair tools. Easy to clear The code.

[diego_demarco]

Quick question guys! I just got my 034 hfc in the mail today with my o2 sensor! I know the install shouldn't be that difficult but I'm always paranoid! I have a good shop (Wolfcar motorsports) in Miami that wants to charge my $330 plus tax to install it! But I have a local buddy (who did my vagcom mods) who offered to do it for $120... Now I just want to know what you guys think? Is it something that I should have the shop do? Or is it fairly simple?

[richardm0025]

Really if you have the right tools (just standard stuff any man should have) and two jack stands and your stock jack to lift up the car you can do it yourself. It's a bitch to do but better than spending the money on such a little thing. I found it fun though. You can get the four bolts off the cat. Using a standard wrench too.


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[richardm0025]

I also use a wrench on the o2 sensors as well.


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[diego_demarco]

Perfect thanks! I guess I'll let my friend do it for $120

[Jerry1847]

Perfect thanks! I guess I'll let my friend do it for $120

Good call. I would have def paid 120 for that install.

[oascom]

I was about do do it by myself... Got all the tools, Pb blaster etc... But then I called shop to ask how much they would charge me with tune together and they told me they will do it for 150+tune cost... I said fuck it for 150 it is wort it.

Lucky me! Shop spend 4h to get that shi.. out. All 4 bolts were stuck and corroded. They had to cut all of them and drill.

Still they charge me only 150 like they said before :)

[diego_demarco]

Yea if the difference was little then I would rather go to a shop lol but we're talking about $120 for someone local to do it or $330 plus tax for the shop to do it lol :/

[247ride]

Just installed a 034 HFC and all this info was super useful.

I ended up removing/installing the cat and downpipe through the top of the engine. I have a MT. No lift. Just jacked the car up , but was not high enough.

Obviously I ran into a few issues. The post cat O2 was a pain to remove. It worked only after really torching it. Heat it up really well and it will eventualy move. Having a special O2 sesor socket helps. And the bolts between the cat and downpipe were seized. I ended up just going to a neighbourhood shop and they removed the bolts for 15 bucks. Before stripping or cutting the bolts, this might save you some time.

[Tm030512]

Do you need "heat paste" on the bolts?? And are the nuts that come with the HFC good for heat?

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[Mod.Kill.Yut.]

Getting the socket on is not the issue. Its getting the nut off without being able to put heat on the nut and being 100% sure your not stripping anything.

also the custom exhaust shop that did my exhaust welded the downpipe to the rest of the exhaust, so that made it alot more fun because there was no way to unclamp it.


And lastly, I put the Euro code on my car, and if you already have a cat-back, prepare for it to get throaty! My exhaust sounds amazing now.

Any chance you can give us a vid so we can enjoy the amazing sounding exhaust as well?

[freshwun]

Just finished my Eurocode HFC install yesterday. Thanks for the instructions. It made the process a lot smoother. Some notes on my install:

1. I was able to remove both O2 sensors while the cat was still mounted.
2. I was able to get to the bottom driver's side turbo bolt from the top (lost the bolt while pulling it out)
3. Definitely need to remove the black plastic cover on the bottom of the car to access the hfc.
4. Broke one of the three threads that connected the hfc to the downpipe. Had to drill it out. Those bolts suck.
5. I was able to pull the original hfc out through the bottom of the car.
6. I installed the EC hfc from the top w/ the O2 sensors on.
7. Used original gaskets and nuts/bolts.
8. Had to replace the downpipe to midpipe clamp bolts/nuts because of rust.

Definitely noticed the car is more responsive. Haven't noticed a different in sound so far. CEL came on this morning while driving to work. Will get APR Stage 2 in the coming months.



2013 Audi B8

[Schrubbe8210]

Just installed a full turboback on my a4. thought i would share some info.

1. all 3 downpipe bolts i got off in about 3 minutes, you need long extensions, and you can get at all of them from the top through the engine bay. the driver side one did require one swivel joint, but even so came off easy.

2. if you take the advice in the post and get the rear o2 sensor out, it makes it a lot easier. put the o2 sensor crows foot on the sensor,plug a universal joint into the crows foot, then an extension into the uni joint, and then you can pound on the extension from the top of the engine to loosen the sensor.

3. with respect to the shock absorbing link, take off the 13mm bolt that goes into the rubber bushing first, since it doesnt have a nut on the other side, and then when you can move around the cat, you can get to the bolt/nut with the spring much easier. the cat also comes out of the car from the bottom much easier.

4. the lower inside turbo bolt is really easy to get at from the top of the engine, if you take a 3/8in ratchet, a 10in extension and a 15mm deep socket, and slip it in so the ratchet handle points up toward the hood. guide the socket with one hand, and then once it is on, you can get the nut off pretty easy.

I should have taken pics, but i always get so damn dirty i dont want to touch my phone.

Last but not least, at all, INSTALL THE NEW EXHAUST FROM THE FRONT TO THE BACK. There is not enough play in the system to weasel the pipes in between the resonators when you get them hung. I put the resonators on the bushings and then went back to put the connecting pipes in, and holy hell was that a bad idea.

it actually wasnt that bad overall.

[Mod.Kill.Yut.]

How bad would it be to drive the vehicle without the secondary O2 sensor for a day or so while I wait for my spacer to come in the mail?


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[o1turbo30v]

Pretty bad, just install it, its easy to get to.

[Mod.Kill.Yut.]

Pretty bad, just install it, its easy to get to.

How so?


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[o1turbo30v]

How so?


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Because you will have a hole in your exhaust after the cat, which means some of your exhaust gases will be getting blown into the engine bay and your interior air inlet which means you will be breathing in exhaust gases, your car will run like crap because every time you let off the gas you will create vacuum at that hole and bring air back in which will cause backfires or worse, your ecu will freak out, your front o2 will not be able to properly adjust your air fuel ratios because it is seeing air coming back into the system from the open hole in your exhaust, etc, etc. Just thread in the 2nd o2 and then remove it when you get your spacer, its right on the top...dont understand why you would not put the 2nd 02 sensor in?

[Mod.Kill.Yut.]

There is a plug on the cat where the O2 sensors go. I just left the plug in. I'm not worried about it because I have another car to drive so not of that stuff you just explained will occur regardless. Thanks for the insight though


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[Nastybutler]

Thanks so much for this How-To! Couldn't have done it without this. Managed to do it all myself in around 8 hours spread out over two days. Day one was removing it, day two was the install, which only took a couple of hours (I know I'm slow). Since my car has less than 6,000 miles on it I didn't have any issues with taking the nuts off either end (other than figuring out how to get enough torque to break the harder to reach ones), and I reused them as well as the gaskets (woe to the next sucker who has to take those nuts off; hopefully not me).

[Tm030512]

Thanks so much for this How-To! Couldn't have done it without this. Managed to do it all myself in around 8 hours spread out over two days. Day one was removing it, day two was the install, which only took a couple of hours (I know I'm slow). Since my car has less than 6,000 miles on it I didn't have any issues with taking the nuts off either end (other than figuring out how to get enough torque to break the harder to reach ones), and I reused them as well as the gaskets (woe to the next sucker who has to take those nuts off; hopefully not me).

Nice to hear it went well for you as well...mine had about 60k mils on it and I found it every easy to remove the bolts.....I got home one night and sprayed the bolts with some penetrating lubricant and extremely morning I did the removal and install no problem

[mkasperzak]

Thanks for the great write-up. Installed my EC HFC and AWE DP on Saturday with no major hiccups, took about 4.5 hours. I used the 10in extension and 15mm deep socket combo to get the 4th bolt (laying on engine) and it came right off. Only thing different for me was that 3 of the studs actually came out of the turbo with the nuts. I used vice and pressure clamps to remove old nuts from the studs and then re-installed studs into turbo.

Car feels great, definitely a little more umpff. Headed in tomorrow to go APR Stage II, but no codes right now with the 034 02 spacer. Wish the HFC/DP combo was a little louder with stock exhaust, but it is definitely a little throatier especially at WOT.

[boomtime]

Thanks for the great write-up. Installed my EC HFC and AWE DP on Saturday with no major hiccups, took about 4.5 hours. I used the 10in extension and 15mm deep socket combo to get the 4th bolt (laying on engine) and it came right off. Only thing different for me was that 3 of the studs actually came out of the turbo with the nuts. I used vice and pressure clamps to remove old nuts from the studs and then re-installed studs into turbo.

Car feels great, definitely a little more umpff. Headed in tomorrow to go APR Stage II, but no codes right now with the 034 02 spacer. Wish the HFC/DP combo was a little louder with stock exhaust, but it is definitely a little throatier especially at WOT.

It is louder and a little bit of a growl... I like it and will probably keep my stock exhaust for this reason.
Also after installing the 034 straight pipe I could hear the turbo spool faintly.

You are going to be surprised by stage 2, I was. Even more so if you had a flexfuel 2.0T
Even still I romped a G35 coupe with exhaust, from a roll-on the other day... on 93 (not e85). It would have been a slaughter with e85.

[inv3rtig0]

Thanks to this DYI my install went totally smooth. 2010 @ 44k miles

The 034 HFC looked very well made, and it fit perfectly. Accessed the bottom bolt by laying on the engine, was able to do it myself by getting the socket + extension on the nut then getting my arm behind the motor to attach the wrench. Used a breaker bar from the top. I could not get one of the bottom nuts back on with the combo wrench so I used a long ass extension and got it from the top. Also hit all the nuts/bolts with power blaster the night before, that stuff works magic. No O2 spacer, drove around the neighborhood and highway for a few minutes, no CEL yet. It feels like the turbo comes up a bit quicker, and I do like the sound, it has a subtle roar now when you have your foot in it. Great mod, now I need the stage 2!

Stock


034

[helldriver]

I plan to do this install this spring , thanks for all the great imformation guys.....

[Fox Fader]

Got my Emusa installed today. Wasn't all that bad, all my bolts broke loose once I got the right setup on them. The 3 lower ones required a little pb and they broke loose. Up top, I got to the hardest bolt from up top through the rear of the engine like a previous poster stated. I left on the mid connetion mount and pulled it all out the top. Can't wait to drive it tomorrow

[heffer]

Can anyone please give me advice on getting the nuts off the turbo loose? I tried getting mine off about a year ago and couldn't get the lower drivers side nut. I tried again the other day quickly but couldn't get any, this was without spraying pb blaster. Any advice would help!

[doowopaudi]

Any idea how much an indy shop would install this for? I'm referring to Audi Specialist (non-dealer prices) shop.

[boomtime]

Can anyone please give me advice on getting the nuts off the turbo loose? I tried getting mine off about a year ago and couldn't get the lower drivers side nut. I tried again the other day quickly but couldn't get any, this was without spraying pb blaster. Any advice would help!

Read my solution under step 6, it worked for me.

[Spm58]

Can anyone please give me advice on getting the nuts off the turbo loose? I tried getting mine off about a year ago and couldn't get the lower drivers side nut. I tried again the other day quickly but couldn't get any, this was without spraying pb blaster. Any advice would help!

I used PB Blaster then breaker bar and some extensions and went from up top behind the engine

[blbroo]

I used PB Blaster then breaker bar and some extensions and went from up top behind the engine

+1

[Nastybutler]

I used PB Blaster then breaker bar and some extensions and went from up top behind the engine

+2

[doowopaudi]

I was about do do it by myself... Got all the tools, Pb blaster etc... But then I called shop to ask how much they would charge me with tune together and they told me they will do it for 150+tune cost... I said fuck it for 150 it is wort it.

Lucky me! Shop spend 4h to get that shi.. out. All 4 bolts were stuck and corroded. They had to cut all of them and drill.

Still they charge me only 150 like they said before :)

Good to know. I hadn't read through all the posts. This is something I plan on getting installed the same day I get my Stage 2 this summer. $150 isn't bad at all.

[Fox Fader]

I used PB Blaster then breaker bar and some extensions and went from up top behind the engine

+3 but no pb or anything needed.