Originally Posted by tommypenguin

This is a write up for installing RV6 Ceramic Coated PreCat Deletes for an 08+ Accord V6 6 speed this write up can likely be used for 4th gen TL owners, likely TSX V6 owners and some other vehicles. I took a lot of pictures on the uninstalling of the stock primary cats, which is 80% of the job. It is not overly difficult as long as you have the right tools and I would budget at least 4 hours for a first timer, possibly 6-8 if you are not a seasoned vet with working on cars. On a scale from 1 to 10 I would say this install would be a 6 for a seasoned vet with tools. In many of the pics I show where I had my ratchet positioned for each nut or bolt, this might be excessive detail for some but I was really bored on one of my vacation days and figured why not show where I was going to position the socket and ratchet for each bolt and nut. This is the way I did it and I provide this disclaimer that if you attempt this install I am not responsible for any ensuing issues with yourself or car you may encounter, DO AT YOUR OWN RISK. I have driven 100 miles since the install and have not had any CELS.

Tools I used:
-3/8” ratchet that has a flexible head
-1/2” torque wrench or1/2” breaker bar
-Various extensions like shown in the pictures below
-Plastic Hose Clamp Pliers
-Needle Nose Pliers
-Right Angle Needle Nose Pliers
-o2 sensor socket
-Flex Head 10mm, 12mm, 14mm ratcheting wrenches
-10mm, 12mm, 14mm short and deep 6 point sockets, preferably tool steel
-Magnet Stick
-Box Cutter or Razor Blade
-16” X 20” Sheet of Cardboard
-PB Blaster
-I used a go through socket for some of the examples but only because I just recently purchased it and wanted to put it to use, a regular flexible ratchet will do
-I also am showing a universal joint and pry below, but I did not use them
-Floor Jack or Ramps and possibly jack stands
-Rubber blocks or something to block the back wheels when the car is lifted
-Good Lighting
-Several Magnetic Bins
-Paper Towels
-Anti-Seeze
-I also recommend having a couple of 8mm X 1.25 thread pitch nuts handy in case you strip a nut or both when removing the bottom nuts to the egr pipe



Engine Bay Front Precat Process:

Make sure your car is ice cold before start so you don’t burn yourself on the exhaust or with scolding hot coolant. Start off by disconnecting both battery cables, which is removing a 10mm from each terminal. Then remove the engine cover which requires a flathead screwdriver. Turn the clips I believe clock wise a ¼ turn and then remove the cover, no pictures were taken for either of those steps, if you needed them to accomplish that portion of the DIY I would suggest shutting the hood and getting the pcds professionally installed before you hurt yourself

I broke the install down into 4 halves, one being everything you will do up top in the engine bay for front and rear, the other half is what you do underneath the car for front and rear pcds. Here is what my engine bay looked like after removing the cover, I didn’t disconnect my battery for this shot and haven’t detailed my engine bay for several months…




Grab your coolant overflow reservoir and pull up on it and pull the container to the side.





After moving the coolant overflow reservoir unscrew the cap going to it and pull the hose out of the coolant overflow reservoir. Wipe any coolant that spilled and wipe the hose with the clean paper towel. Then grab your plastic hose clamp pliers and clamp the end of the hose shut so no additional coolant will leak out.





Then pull the reservoir out and set it somewhere out of the way. I also grabbed a brand new clean latex glove and stuffed it in the fill hole so no dirt or grime would get inside.



After that is out of way you can go ahead and disconnect the front top and bottom o2 sensors from the harnesses. First grab and squeeze the bottom of the harness on the left clip, then pull down and the harness will be removed from its metal retainer.



The grab and squeeze the top of the harness on the left with your right hand and separate the bottom connector from the harness.



Then do the same for the harness on the right for the bottom o2 sensor.





After doing that remove the 14mm bolt that holds the bracket to the wiring harness for the o2 sensor.


Then you need to pop the zip tie clip out of the bracket that is holding the electrical harness that is not for the o2 sensors out using needle nose pliers.








Next if you follow the bottom front o2 sensor wire down you will see it is clipped to a bracket that is connected to the slave cylinder on the 6-6. I believe it is a 10 or 12mm bolt, use a slew of extensions or if you have a really long one use that and remove the bolt.





Remove one of the passenger side radiator fan bolts up top, I believe they are 10mm.



Loosen the other one but do not remove it yet because there are two to remove underneath the car going to the bottom of the fan, if you remove both up top and then both on the bottom the fan could fall and get damaged, when it is ready to come out you want to do so from the top of the car.



If you are standing at the front of the car and look down on the right side of the passenger fan you will see a clip I am pointing to with my pliers in the pic. I used my hands and pulled the plug off the metal retainer like you did with the o2 sensor then disconnect the plug from its harness. This might take you a minute or two but you will get it.





Then disconnect the two I believe they are 10mm bolts that hold the coil pack insulator bracket on and set the insulator bracket out of the way.





In the pics above I already have the piece of cardboard pay no attention to that, I learned I needed to remove the insulator bracket when trying to pull the front pcd out.

Remove the two 12mm bolts holding the top of the egr pipe to the block.




Then put your o2 sensor socket on the top o2 sensor with an extension I used a 6” one and hold the harness for the o2 sensor straight up with your left hand so it doesn’t swing around and potentially get damaged while you remove the top o2 sensor with your right hand ratcheting.



I removed the top 2 heatshield bolts to the front precat but it was brought to my attention from a member named peter on my8g that it is unnecessary to remove the front precat heatshield to remove the precat. He undid the bolts I’ve shown this far and I believe he also remove the nut holding the middle spark plug coil pack, then removed that coil pack. Then he removed the o2 sensor on the bottom, disconnected the bracket bolt to the pcd and the bolts from the j pipe to pcd after removing the passenger side fan and removed the front precat with the egr tube still connected to it. I will still show my pics of removing the heat shield from the front precat since it worked for me but I wish I would have given his method a shot after reading it.

Below are pics of me removing the 10mm bolts for each side of the front precat heat shield, I would not do this unless you find it necessary…





You can now remove the 3 of the 4 nuts that hold the pcd to the engine block and loosen 1 of the 4 so its almost ready to come off. Again I did this so when I removed all nuts and bolts on the bottom the pcd would fall off the studs to the block and possibly damage anything.







Top of Engine Rear Precat Process:

I have the UR strut bar, so my removal of that bar and the hose that connects to my strut bar will be slightly different than removing the stock strut bar. IIRC you only have to remove 3 nuts on each side of the strut tower and pull the hose up off the hooks of the strut bar to pull it off. On mine I have to remove all 6 nuts on each side of the strut tower and disconnect my hose to the strut I used zip ties to secure. There are 3 nuts that are 12mm and 3 that are 14mm, on the stock strut bar I believe you only need to remove the 3 12mm, someone could clarify.












Then remove the I believe it’s a 10mm bolt that holds the power steering hose bracket in place. I am pointing to it with my wrench.







Remove the 10mm nut to the coil pack that is closest to the passenger side. But do not pull the coil pack out yet.





Then remove the two 10mm bolts that hold the rear coil pack insulator bracket.







Disconnect the two o2 sensor plugs to their corresponding harnesses just like you did for the front o2 sensors, it may be more of feel unless you lean onto the hood for a vantage point.





Remove the top rear o2 sensor with an extension and your o2 sensor socket.





Remove the top two heat shield bracket 10mm bolts with a 10mm ratchet if any of the bolts spin and won’t come out you need to place a 12mm closed end wrench on the nut on the opposite side of the bolt, I had to do this for one of the two heat shield nuts.







Remove 3 out of the 4 nuts that hold the rear pcd to the engine block.









After doing this clean the area around the coil pack with a detailer or cleaner of your liking go ahead and pull the loose coil pack out, it will literally pull right out. Then I put a brand new clean latex glove in the coil pack hole to prevent anything from falling into the hole. You are done with the upper portion of the rear precat delete removal.


If you haven’t already clean jack up the car, sweep the area you are to be working on underneath the car and support it safely then get underneath it.

Front Precat Underneath Car Removal Process:

Remove the 3 14mm or 12mm nuts(can’t remember) that connect the j pipe to the PCDS, you do not need to remove the j pipe to do this install and IMO it wouldn’t provide any additional leverage or clearance.

Remove the 14mm bolt that connects the bracket to the front precat using a flex head ratcheting wrench.





Remove the two 10mm bolts that hold the bottom of the radiator fan to the radiator. Also the wire harness has a plastic zip tie clip you need to squeeze with pliers and push out to disconnect it from the fan. At this point you can get back up top, remove the last bolt you left on and pull the radiator fan out the top. Then insert your 16” X 20” piece of cardboard you cut with your box cutter and place it in front of the radiator, mark where the top two bolts would go. Then pull the card board out and puncture two holes in the cardboard with a screwdriver so that you can screw the bolts in to the top to hole the cardboard in place.





Lastly underneath the car pull the wiring harness and the corresponding brackets that go to the bottom o2 sensor through. Then put your o2 sensor socket on the front bottom o2 sensor and remove it. At this point you can either remove the last 2 10 mm heatshield bolts on the bottom of the front precat or attempt to go up top, remove the last nut you have holding the front precat and pull it out the top with the egr pipe connected. If you attempt to remove the two nuts that hold the EGR pipe to precat DO NOT ATTEMPT TO REMOVE THE NUTS FROM UNDERNEATH THE CAR. I tried this and stripped one of the nuts badly because the nut was crusted on heavily even after several liberal sprays of PB Blaster I could not get the nut off with a 6 point wrench or socket underneath. I was however able to stand up grab my ½” torque wrench facing the front of the car, used and extension and an impact 12mm socket and removed the nut. I reiterate I would attempt removing the front precat first with heatshield and egr pipe attached and see how it goes, if you can’t do as I suggested. If that works remove the egr pipe nuts to the pcd with a torque wrench and impact socket while its out of the car.





Rear Precat Underneath Car Removal Process:

Remove the 3 12mm or 14mm nuts that connect the j pipe to the precat delete first.






Then remove the 14mm bolt that holds the bracket to the pcd.





Remove the bolt that holds the bracket to the wire for the bottom o2 sensor I believe it is also a 14mm.





Then remove the bottom o2 sensor. I set it off to the drivers side so it wasn’t hanging. Remove the bottom two heat shields 10mm bolts.





You are now ready to get up top and grab the heat shield closest to the firewall and pull it out. The bottom driver side corner of it was in very tight but after a couple minutes of manipulating it, it came out. After doing so remove the loose 14mm nut you left on one of the 4 studs for the pcd to the engine and pull the pcd without the other heat shield attached out the top.



You are now ready to install PCDs in reverse order. Only additional advice I have is to put the pcd in the front and rear, make sure the studs on the bottom go through the j pipe, then slide it on the studs to the block and very loosely put nuts on each stud on the top and bottom. Then make sure you can insert the bracket bolt loosely into the bracket hole on pcd. Then loosely install the nuts on to the egr pipe or install that pipe while its out of the car along with o2 sensors, its your preference. Once everything is lined up, start by tightening the pcd to engine block criss crossing when tightening and tightening in 3 stages. 75%, 90%, 100% tight. Then tighten the egr pipe, the bracket bolt and then the j pipe to pcds. Do the same for the rear pcd sans the egr pipe since there is not one for the rear and get driving. I suggest you use at least 2 resonators unless you like an ultra loud exhaust with a lot of rasp. The power gain from PCDs have provided the most noticeable gain yet and I have done all bolt ons to my 6-6 below are some remaining pics I took of the installed product.















Showing how I ran the wire for the rear bottom o2 sensor.





Showing how I ran the wire for the front bottom o2 sensor.







Double check all bolts, make sure they are tight make sure everything has been reinstalled correctly. Enjoy, thanks for reading and I hope this helps someone out in the future since it took just a couple minute or two to write up. Remember if you strip either of the 2 nuts that go to the egr pipe to pcd, the nuts can be had at ace for 91cents a pop, size is 8mm by 1.25 thread pitch.